Chapter 2 Biology Study Guide – Flashcards
Unlock all answers in this set
Unlock answersquestion
nucleus
answer
atom's central core.
question
proton
answer
positively charged, found in the atomic nucleus
question
neutron
answer
no electrical charge, found in the atomic nucleus
question
electron
answer
negatively charged, surround the nucleus in a "cloud" ; orbit the nucleus Can only have 2 electron charges on shell. - orbit the nucleus of an atom in specific electron shells. - number of ___ in the outermost shell determines the chemical properties of an atom.
question
energy levels
answer
represented by electron shells
question
potential energy
answer
energy that matter possesses because of its location or structure
question
energy
answer
the capacity to cause change
question
isotopes
answer
alternate mass forms of an element. they have the same number of protons and electrons. But they have a different number of neutrons
question
atomic number
answer
number of protons of an element
question
mass number
answer
sum of protons + neutrons in nucleus of an atom.
question
atomic weight
answer
...
question
valence shell
answer
The outermost shell
question
polar covalent bond
answer
atoms have differing electronegativities; share the electrons unequally. Example : H2O: O - / + H + H
question
nonpolar covalent bond
answer
atoms have a similar electronegativities; share the electron equally. Example Oxygen gas (O2): O=O
question
essential elements
answer
include carbon, hydrogen, oxygen, and nitrogen. Make up of 96% of living matter.
question
ionic bond
answer
an attraction between anions and cations. Be able to draw example.
question
hydrogen bond
answer
froms when a hydrogen atom covalently bonded to one electronegative atom is also attracted to another electronegative atom. Be able to draw example.
question
covalent bond
answer
the sharing of a pair of valence electrons. Forms when two atoms share one or more pairs of outer-shell electrons. Be able to draw example. MAKE A TRIANGLE SHAPE Example: H²O: O-H | H
question
single bond
answer
sharing of one pair of valence electrons H²: H-H two hydrogen atoms can form a ____.
question
double bond
answer
sharing of two pairs of valence electrons O²: O=O two oxygen atoms share two pair of electrons to form a ___.
question
ion
answer
atoms with more or fewer electrons than usual; charged atoms.
question
cation
answer
positively charged ions
question
anion
answer
negatively charged ions
question
element
answer
consists of a certain kind of atom that is different from those of other elements.
question
molecule
answer
consists of two or more atoms held together by covalent bonds.
question
compound
answer
a substance consisting of two or more elements combined in a fixed ration. Has characteristics different from those of its elements.
question
valence electrons
answer
those in the outermost, or valence shell. determine the chemical behavior of an atom.
question
electronegative
answer
the attraction of a particular kind of atom for the electrons in a covalent bond. the more ____ an atom, the more strongly it pulls shared electrons toward itself.
question
What is the difference between an element and a compound
answer
Elements and compounds are pure chemical substances found in nature. The difference between an element and a compound is that an element is a substance made of same type of atoms, whereas a compound is made of different elements in definite proportions.
question
Describe the structure of an atom
answer
smalled unit of matter that still retains the properties of an element. Composed of even smaller parts called subatomic particles.
question
Define and distinguish among atomic number, mass number, and valence shell
answer
The atomic number is the number of protons, which is located on top of the element symbol. The mass number is the number of protons+ neurons. Located below the element symbol. The valence shell is the outer most shell. It determines the chemical behavior of an atom.
question
Given the atomic number and atomic weight of an atom, determine the number of neutrons
answer
Number of Neutrons = Mass Number - Atomic Number
question
How does an isotope differ from a normal atom?
answer
...
question
Explain how electron configuration influences the chemical behavior of an atom.
answer
...
question
Explain the differences between non polar covalent, polar covalent and ionic bonds.
answer
In a nonpolar covalent bond, the atoms have similar electronegativities. They share the electron equally. example: O2: O=O In a polar covalent bond the atoms have differing electronegativities; share the electrons unequally.
question
Describe the formation of a hydrogen bond and explain how it differs from a covalent or ionic bond.
answer
...
question
How does an ionic bond differs from a covalent bond?
answer
...
question
From the number of electrons in an atom, predict how many bonds an atom might form
answer
...
question
How does electronegativity influence the formation of chemical bonds?
answer
...
