atomic structure/electrons

Question 1

democritus

Answer 1

atomos: undivided

could not be divided, created, or destroyed

Question 2

aristotle

Answer 2

four elements: fire, water, air, and earth

Question 3

lavoisir

Answer 3

father of modern chemistry
law of conservation of mass
33 elements

Question 4

proust

Answer 4

law of definite proportions

Question 5

john dalton

Answer 5

law of multiple proportions: the mass ratio for elements can be expressed in small, whole numbers
first table elements by mass
dalton’s atomic theory

Question 6

daltons atomic theory

Answer 6

1. all matter is made up of atoms
2. all atoms of a given element are identical in mass and properties
3. compounds are formed by a combination of two or more atoms
4. a chemical reaction is a rearrangement of atoms

Question 7

j.j. thomson

Answer 7

cathode ray experiment in 1897: electrons have negative charge, charge to mass ratio, and both + and - particles are present
plum pudding model in 1909

Question 8

robert millikan

Answer 8

“oil drop experiment” in 1908

used to calculate mass of electron

Question 9

ernest rutherford

Answer 9

gold foil experiment in 1911

nuclear atomic model in 1910: the nucleus is dense and mostly empty space

Question 10

niels bohr

Answer 10

modern model of the atom: dense nucleus surrounded by orbiting electrons

Question 11

erwin shrodinger

Answer 11

proposes wave mechanical model of electron

Question 12

james chadwick

Answer 12

nobel peace prize for discovering neutron

Question 13

max planck (and equation)

Answer 13

said energy is quantized and can only be absorbed in small whole number multiplies related to frequency
e=hv defines one quantum/photon of energy

Question 14

einstein

Answer 14

emr is a stream of photons (little packets of energy) with mass and energy

Question 15

de broglie

Answer 15

emr has wave and particle characteristics

Question 16

bohr

Answer 16

calculated the wavelength of a photon emitted by hydrogen electron

Question 17

electromagnetic

Answer 17

waves of electric and magnetic fields at right angles to each other

Question 18

radiation

Answer 18

menergy that travels and spreads as it goes out (radiates out from charged particles)

Question 19

electromagnetic radiation spectrum

Answer 19

radio waves, microwaves, infrared, ultraviolet radiation, x-rays, and gamma rays

Question 20

heisenberg uncertainty principle

Answer 20

impossible to know the exact location and momentum of an electron at the same time so it ruled out define locations for electrons

Question 21

wavelength

Answer 21

distance between any point on a wave and the corresponding point on the next wave

Question 22

frequency

Answer 22

how many wavelengths pass a fixed point in a given time

Question 23

speed of propagation

Answer 23

(c) rate at which wave travels through space

as frequency increases, wavelength decreases

Question 24

photoelectric effect

Answer 24

einstein

metals emit electrons when struck by light

Question 25

particle vs wave

Answer 25

particle is localized and wave is delocalized | particle is matter and wave is energy

Question 26

wave-particle daulity

Answer 26

light can show wave or particle behavior

Question 27

atomic emission spectra

Answer 27

each element has a unique emission spectra

Question 28

rydberg formula for hydrogen

Answer 28

full spectrum of emission from hydrogen

Question 29

bhor atomic theory and its flaws

Answer 29

introduced quantum concept into atomic theory predicted emission spectrum of hydrogen only worked for hydrogen and other one-electron systems

Question 30

quantum mechanical model

Answer 30

behavior of the electron described by a set of allowed wave functions (Ψ) called orbitals each wave function has definite energy electron moves between orbitals by absorbing/emitting quantum of energy equal to the energy difference between the states (similar to bohr model).