Chemistry Glencoe Ch. 4, 5, 6 – Flashcards
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Unlock answersDemocritus |
-person that created the term, "atom" -1st to propose matter was not infinitely divisible believed atoms couldnt be created, destroyed, or further divided -atoms solid, homogeneous, indestructible, vary in size and shape |
Dalton |
-person that said atoms of element = identical, in chem. reaction, atoms are separated, combined, and rearranged -atoms cant be created, divided, destroyed -diff. atoms combine in simple whole-number ratios to form compounds |
Crookes |
-person that accidentally discovered "cathode ray" -studied typical tube used by researches studying relationship between mass and charge -led to invention of television |
cathode |
electrode connected to negative terminal of battery |
anode |
electrode connected to positive terminal of battery |
cathode ray |
ray of radiation originated from the cathode end of tube |
stream of charged particles |
Scientists were convinced that cathode rays were actually a ______ ___ _______ ___________. |
Negative charge |
particles of cathode rays carried a what charge? |
Thomson |
-person that began series of cathode ray tube experiments to determine charge-to-mass ratio of charged particle -concluded DALTON WAS WRONG -identified the electron(first subatomic particle) |
Millikan |
-person to determine charge of electron |
1/840 |
The mass of an electron is what fraction the mass of a hydrogen atom? |
Plum Pudding Model/Chocolate-Chip Cookie Dough Model chocolate chips = electrons dough=uniformly distributed positive charge |
-consisted of spherically shaped atom composed of uniformly distributed positive charge within which the individual negatively charged electrons resided |
Rutherford |
-person that studied how positively charged alpha particles interacted with solid matter -see if alpha particles would be deflected as they passed through a thin of foil of gold - calculated that atom consisted mostly of empty space through which electrons move, concluded there was a tiny, dense region, called the nucleus-centrally located within atom that contained all of an atom's positive charge and virtually all of its mass - concluded nucleus contained positively charged particles (protons) |
Gold Foil Experiment |
- narrow beam of alpha particles-aimed at thin sheet of gold foil, zinc sulfide coated screen surrounding gold foil produced flash of light whenever struck by alpha particle - few of alpha particles were deflected at very large angles, several deflected straight back toward source -because nucleus occupies such a small space and contains most of an atom's mass, it is incredibly dense - electrons move rapidly through empty space |
10,000 times the diameter |
An atom's diameter is ______ times the diameter of a nucleus |
Chadwick |
showed nucleus contained another subatomic particle (neutral-neutron) |
Neutron |
- has mass nearly equal to proton, carries no electrical charge |
Atoms |
spherically shaped, electrons held within by their attraction to the positively charged nucleus |
neutral neutrons and positively charged protons, also contains all of atom's positive charge and more than 99.97% of its mass |
The nucleus is composed of what? |
Quarks |
Protons and neutrons are made up of particles known as what? |
Moseley |
-person that discovered that the number of protons and electrons in an atom must be equal because all atoms are neutral. - Once you know atomic #, you know # of protons and electrons |
Isotopes |
atoms with same number of protons but different numbered of neutrons, differ in mass, same chemical behavior |
Mass Number |
represents sum of number of protons and neutrons in nucleus |
Mass number - atomic number |
How do you calculate the number of neutrons an atom has? |
1/1840 |
The mass of an electron is what fraction of a proton or neutron? |
carbon-12 atom |
What chosen atomic standard do scientists use to measure mass of an atom? |
Atomic Mass Unit (AMU) |
defined as 1/12 mass of carbon-12 atom |
Atomic Mass |
the weighted average mass of the isotopes of that element |
Nuclear reactions |
involve an atom of one element changing into an atom of another element -change occurs in nucleus |
Radioactivity |
some substances spontaneously emitted radiation in process |
Radiation |
rays and particles emitted by radioactive material |
because nuclei are unstable |
Why do radioactive atoms emit radiation? |
Radioactive Decay |
-unstable nuclei lose energy by emitting radiation in a spontaneous process - unstable atoms undergo this until they form stable nonradioactive atoms, often of different elements |
Alpha Radiation |
negatively charged plate, made up of alpha particles, each containing two protons and two neutrons, thus has a 2+ charge -opposite electrical charges attract |
Beta Radiation |
-consists of fast moving electrons - 1- charge |
Gamma Radiation |
high-energy radiation that possess no mass, no electrical charge- gamma rays not deflected by electric or magnetic fields |
electromagnetic radiation |
form of energy that exhibits wavelike behavior as it travels through space |
visible light, from the sun, microwaves, x-rays, waves that carry radio and television programs to your home |
List examples of electromagnetic radiation. |
Wavelength |
shortest distance between equivalent points on continuous wave - measured from crest to crest, or from trough to trough -expressed in m, cm, or nanometers |
Frequency |
number of waves that pass a given point per second -one hertz (Hz) - SI unit of frequency = one wave per second |
Amplitude |
the wave's height from the origin to a crest or from the origin to a trough |
same, differ |
The speed of electromagnetic waves is the _____, but may _____ in wavelengths and frequencies.....inversely related, as one increases, the other decreases |
Electromagnetic spectrum |
encompasses all forms of electromagnetic radiation, with only difference in types of radiation being their frequencies and wavelengths |
The Quantum Concept |
states that different colors correspond to different frequencies and wavelengths |
Max Planck |
- person that began searching for explanation as he studied light emitted from heated objectes -started QUANTA |
Quantum |
minimum amount of energy that can be gained or lost by an atom - led scientists to believe that energy could be absorbed and emitted in continually varying quantities, with no minimum limit to the amount |
Planck's Constant E quantum |
hv value of 6.626 x 10-36 J s, where J is the symbol for juole, the SI unit of energy. Looking at the equation, energy of radiation increases as the radiation's frequency, v, increases. Equation explains why violet light has greater energy than red light |
Photoelectric effect |
Photoelectrons are emitted from a metal's surface when light of a certain frequency shines on the surface. Photoelectric cells in calculators and many other devices convert the energy of incident light into electrical energy. |
Photon |
a particle of electromagnetic radiation with no mass that carries a quantum of energy |
Atomic emission spectrum |
the set of frequencies of the electromagnetic waves emitted by atoms of the element, not a continuous range of colors - each elements' is unique and can be used to determine if that element is part of an unknown compound |
Ground state |
the lowest allowable energy state of an atom |
Excited state |
when atom gains energy |
Bohr's model |
- suggested single electron in hydrogen atom moves around nucleus in only certain allowed circular orbits -smaller electron's orbit= lower atom's energy state/level - assigned a quantum number, n to each orbit and even calculated orbit's radius -ground state in n=1 orbit, when energy is added from outside source,electron moves to a higher-energy orbit (n=2), such transition raises atom to excited state -electron can drop from higher-energy orbit to lower-energy orbit |
De Broglie equation |
predicts that all moving particles have wave characteristics |
Heisenberg uncertainty principle |
states that it is fundamentally impossible to know precisely both the velocity and position of a particle at the same time |
Schrodinger |
-person that furthered wave-particle theory proposed be de Broglie, formed equation that treated hydrogen atom's electron as a wave |
Quantum mechanical model of the atom |
atomic model in which electrons are treated as waves |
atomic orbital |
a three-dimensional region around nucleus -describes electron's probable location |
Principal quantum numbers |
indicate relative sizes and energies of atomic orbitals - as n increases, orbital becomes larger, electron spends more time farther from nucleus -as atom's energy level increases, n specifies atom's major energy levels- principal energy levels |
shapes of atom's orbitals:
S= sphere P= perpendicular D= 5 orbitals F= 7 orbitals |
Energy sublevels are labeled s, p, d, or f according to what? |
Electron configuration |
arrangement of electrons in an atom |
Aufbau Principle |
states that each electron occupies the lowest energy orbital available -your step in determining an element's ground-state electron configuration is learning the sequence of atomic orbitals from lowest energy to highest energy...
In order of increasing energy, sequence of energy sublevels within a principal energy level is s, p, d, f |
Pauli exclusion principle |
states that a max of two electrons may occupy a single atomic orbital, but only if the electrons ave opposite spins
-arrow up represents electron spinning in one direction, arrow pointing down represents it spinning in opposite direction |
Hund's Rule |
states that single electrons with the same spin must occupy each equal-energy orbital before additional electrons with opposite spins can occupy the same orbitals |
valence electrons |
defined as electrons in the atom's outermost orbitals |
John Newlands |
person that named "periodic relationship" |
Mendeleev |
person that arranged according to atomic mass (wasnt correct though) |
Moseley |
Who discovered to arrange the periodic table by protons? |
Metals |
shiny, good conductors of heat and electricity, malleable, ductile |
Alkali and alkaline earth metals |
chemically reactive...
|
Alkali |
Which is more reactive? alkali or alkaline earth metals? |
Lanthanide and Actinide |
What are the two sets of inner transition metals? |
Nonmetals |
generally gases or brittle, dull looking solids, poor conductors |
Bromine |
Name the only nonmetal that's a liquid at room temperature |
Halogens |
7A - highly reactive |
Noble gases |
8A - extremely unreactive |
Metalloids |
semimetals |
s-block: 1A, 2A p-block: 3A-8A d-block: transition metals and is largest of blocks f-block: inner transition metals |
Where on the periodic table are these located? s-block? p-block? d-block? f-block? |
Within periods - decrease in atomic radii moving left-to-right Within groups- atomic radii increase as you move down, nuclear charge increases, and electrons added to higher principal energy levels |
State the periodic trends for Atomic Radius |
Ion |
atom or a bonded group of atoms that has a positive or negative charge |
Within periods: positive ions decrease left-to-right Within groups: down- higher principal energy levels |
State the periodic trends for Ionic Radius |
Ionization energy |
the energy required to remove an electron from a gaseous atom |
Within periods: increase left-to-right Within groups: decrease as you move down |
State the periodic trends for Ionization energy. |
Octet Rule |
states that atoms tend to gain, lose, or share electrons in order to acquire a full set of eight valence electrons - elements on left side of table tend to lose electrons and form positive ions |
Electronegativity |
indicated relative ability of its atoms to attract electrons in a chemical bond |
Within periods: increases as you move left-to-right Within groups: decrease as you move down |
State the periodic trends for Electronegativity |