biology unit 1 – Flashcards
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living things maintain a stable internal _________
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environment
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living things obtain and use materials and ________
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energy
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genetic molecule common to all living things is ________
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DNA
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internal process of ________ enables living things to survive changing conditions
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homeostasis
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living things are capable of responding to different types of _____
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stimuli
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living things have a long history of ________ change
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evolutionary
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the continuation of life depends on both ________ and _________
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asexual reproduction sexual reproduction
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combination of chemical reactions that make up an organism's _________ help to organize raw materials into living matter
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metabolism
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cellular basis of life
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living things are made up of cells
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information and heredity
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DNA, universal genetic code
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organisms use matter and energy to live
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life requires matter the provides raw materials, nutrients, and energy
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homeostasis
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living things maintain a relatively stable internal environment
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evolution
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change in groups of organisms over time
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all living things have structures that have specific functions to help them live
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each major group of organisms has evolved structures that make particular functions possible
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diversity and unity
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all living things are fundamentally similar at the molecular level
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interdependence
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all forms of life on earth are connected into a biosphere--a living planet
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science as a way of knowing
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scientific method (science is a process based on theory not facts)
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"That boy shot up five inches in only one year."
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growth
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"Our cat had a litter of kittens yesterday."
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reproduction
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"My dog has become much less clumsy now that he is a year old."
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development
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"Eat a good breakfast and you will be able to run longer."
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metabolism
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"When that car pulled in the driveway, my cat ran to hide under the porch."
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responding to stimuli
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"That owl's night vision allows it to see the movement of mice on even the darkest night."
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natural selection
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"Single-celled organisms live in the pond behind school."
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bacteria
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your body normally maintains a temperature of 98.6 degrees F
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homeostasis
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giraffes use their long neck to eat from the high branches of a tree
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natural selection
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_______ is another name for "living thing"
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organism
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chemical element is a pure substance that consists entirely of one type of ______
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atom
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atoms of the same element that differ in the number of neutrons they contain are called ______
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isotopes
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atom is made up of protons, neutrons, and _______
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electrons
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________ and _______ are located in the nucleus
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protons and neutrons
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What is a chemical compound?
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two or more chemically combined elements
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What do the formulas for table salt, NaCl, and water, H2O, indicate about these compounds?
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what elements and proportions are used to create the compounds (NaCl=1:1, H2O= 2:1)
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What is the difference between an ionic compound and a covalent compound?
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Ionic transfer electrons Covalent share electrons
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How are chemical bonds important in a metabolism?
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release/break of bonds provides energy
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three particles that make up atoms are
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protons, neutrons, and electrons
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what are found in the space surrounding the nucleus of an atom?
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electrons
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isotopes are atoms of the same element with the same number of protons and a different number of
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neutrons
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what is formed by the chemical joining of two or more elements in definite amounts?
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compound
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what type of ion forms when an atom loses electrons?
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positive (cation)
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all isotopes of an element have the same number of ______ and ______
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protons and electrons
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chemical bond formed by the transfer of electrons is a(an)_______
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ionic bond
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describe how a sodium atom forms a bond with a chlorine atom
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sodium and chloride form an ionic bond because sodium is a metal with a charge of 1+ and chlorine is a nonmetal with a charge of 1-. The cation, sodium, gives an electron to the anion, chlorine.
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Why are atoms considered neutral?
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atoms are considered neutral because they have equal numbers of protons and electrons
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explain a covalent bond
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bond between metals that share electrons
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what atom in water have a more negative charge?
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oxygen
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what atom in water have a more positive charge?
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hydrogen
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what kind of bond holds water molecules together?
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hydrogen bonding
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what keeps water flowing in a stream rather than dispersing into a bunch of separate water molecules?
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cohesion
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Water is polar, so ______ substances dissolve in it, and ______ do not.
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polar do, non-polar do not
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hydrophobic
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fears water, non-polar, non-dissolving (in water)
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hydrophilic
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water loving, polar, dissolving (in water)
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why does it make sense that our cell membranes are made of lipids?
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to hold water in
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what property causes a meniscus in a graduated cylinder filled with water?
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adhesion
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DNA
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complex molecules that store info needed to live
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stimuli
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signal in environment to which organism reponds
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sexual reproduction
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cells from 2 parents unite to produce NEW organism
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asexual reproduction
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single cell produces IDENTICAL organism to itself
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homeostasis
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condition where organism maintains in internal environment despite changes in exterior environment
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simple molecules
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ordered together in larger macromolecules
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cells
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basic unit of life
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made up of one or more cell, makes it a
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living thing
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viruses
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"borderline organisms" cannot reproduce unless infect another organism
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not infecting cell=
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not living cell
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bacteria are all
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unicellular
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not all unicellular things are
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bacteria
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humans are ____-cellular, meaning they are made of many cells
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multi(cellular)
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earth is ______ years old
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4.6 billion
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life on earth is ______ years old
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3.5 billion
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hierarchy of life (bottom to top)
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atoms molecules macromolecules organelle cells tissues organs organ systems organism population community ecosystem biosphere
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hierarchy of life is a way of _________
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interdependence
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chemical reactions occur to keep living things _____
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alive
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basic unit of matter
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atom
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Democritus
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Greek philosopher who discoverd the atom
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"atomos"
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means unable to cut
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element
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pure substance containning only one type of atom
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atomic number
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number of protons unique to each element
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atomic mass
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average of isotopes mass number number of protons plus the number of electrons
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physical and chemical properties of a compound _____ from original elements' its composed of
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differ
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valence electrons
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electrons available fin outermost shell for chemical bonds determine chemical behavior of atom
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single bond
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2 e- shared
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double bond
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4 e- shared
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triple bond
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6e- shared
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molecule
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smallest unit of compounds
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van der waals forces
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atoms of different elements have different ability of attraction atoms in covalent bond share electrons, but not equally creates tiny (partial) positive or negative charge not as strong as covalent bonds or ionic bonds
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matter
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takes up space has mass
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deficiencies
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deficiency of an essential element results in disease
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trace elements
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required by organism in minute quantities ex: minerals such as Fe and Zn
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properties of matter
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depend on structure of its atoms
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absorbed energy
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gaining energy moves to higher shells
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losing energy
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moves to lower shells
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potential energy
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energy matter possesses because of location or source
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kinetic energy
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energy of motion
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energy levels are represented by
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electron shells
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chemical behavior of an atom is defined by its
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electron configuration and distribution
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orbitals
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3D space where electron found 90% of time consists of specific number of orbitals each can hold up to 2e_
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electronegativity
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the attraction of a particular kind of atom for electrons in a covalent bond more electronegativity = more strongly it pulls shared electrons towards itself
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non-polar covalent bond
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atoms have similar electronegativities share the electrons equally
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polar covalent bond
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atoms have different electronegativites share electrons unequally
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anion
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negatively charge ion
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cation
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positively charged ion
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ionic compunds
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salts which can form crystals
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weak chemical bonds
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reinforce shapes of large molecules help molecules adhere to eacother
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s and p orbitals may _______, creating specific molecular shapes
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hybridize
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subatomic particles
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protons neutrons electrons
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diatomic
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two of the same elements have to be linked together (I,Br,Cl,F,O,N,H) 7 diatomic elements
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types of formulas
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molecular-same empirical formula but with exact amounts (most exact) empirical- tells kinds of elements and ratios (simple ratio) structural-shape
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ionic bond is a _______ and _______
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metal and non-metal
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metals
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cation on left of periodic table charge depends on group # (column) give up electrons
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nonmetals
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anions on right of periodic table charge depends on 8-group # (one's place) gain electron
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catabolism
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chemical reactions that break things down (release energy)
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anabolism
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chemical reactions that build things up (capture energy)
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water's electrons found near _______
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oxygen nucleus
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cohesion produces
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surface tension
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capillary action
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draws water up plant's roots
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water's heat capacity
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high b/c large amount of heat needed to make molecules move faster due to hydrogen bonds
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water is not always pure
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ex: found in mixture
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mixture
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material composed of 2+ elements or compounds that are physically mixed together but not chemically combined
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2 types of mixtures
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solutions and suspensions
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solution
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all components evenly distributed solute and solvent
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solute
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dissolved
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solvent
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dissolver
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water is the greatest______ on earth
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solvent
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suspension
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mixture of water and nondissolved solutes
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blood is an example of
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solution and suspension
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water molecules sometimes split to form ___
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ions
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pH scale
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measurement system to indicate concentration of H+ ions in a solution
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basic
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below 7 pH
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acidic
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above 7 pH
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buffers
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weak acids or bases that produce quick changes with strong acids or bases
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properties due to hydrogen bonds
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cohesion resists change in temp high heat vaporization expands when freezes versatile solvent
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surface tension
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measure of force necessary to stretch or break the surface of a liquid relates to cohesion
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water moderates temp. on earth
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stabilizes air temp. by absorbing warmer air and releasing heat to cooler air
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Celsius scale at sea level of water temps.
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100C-boils 37C-human body temp 23C-room temp 0C-freezes
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specific heat
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amount of heat that must be absorbed/lost for one gram of substance to change its temp by one degree celcius
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water on earth produces "heat sink"
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gives coastal areas mild climate stables marine environment prevents heat fluctuations outside range suitable for life
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evaporative cooling of water
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moderates earth's climate stabilizes temp in aquatic ecosystems prevents organisms from overheating
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density of water
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most dense 4C contracts at 4C expands from 4-0C prevents water from freezing bottom up
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ice forms on surface first
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freezing of water releases heat to water below to create insulation
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crystal lattice of water at 0C
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each molecule bonded with max of 4 partners ice melts, bonds break
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2 important quantitative properties of aqueous solutions
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concentration pH
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molecular weight
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sum of weight of atoms in molecule in daltons
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mole
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amount of substance that has amass in grams numerically equivalent to its molecular weight in daltons
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molarity
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concentration of a material in solution
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dissociation of water molecules
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occasional switch of one hydrogen atom leaving H2O to another H2O results in hydronium H3O and OH
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strong acids and bases
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completley dissociate in water
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weak acids and bases
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only partially/reversibly dissociate
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most biologic fluids are in the pH range of _____
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6-8
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pH scale represents tenfold differences
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logarithmic scale small change in pH is a dramatic change in H+ and OH- concentrations
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intra
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means inside of molecules
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inter
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means between molecules
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dotted line represents _______ bond
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hydrogen
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solid line represents _________ bond
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covalent
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Why do trees have capillary action with small tubes rather than large tubes?
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small tubes have less of a meniscus so water can adhere all the way up to the top of the tree
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