Physics Ch 9. Atomic and Nuclear Phenomena

Question 1

Photoelectric effect

Answer 1

Ejection of an electron from the surface of a metal in response to light, ejected electrons create a current, the magnitude of the skirt is proportional to the intensity of the incident beam of light

Question 2

Threshold frequency

Answer 2

The minimum light frequency necessary to eject an electron from a given metal

Question 3

Work function

Answer 3

The minimum energy necessary to eject an electron from a given metal, it’s value depends on the metal used and can be calculated by multiplying the threshold frequency by Planck’s constant, the greater the energy of the incident photon above the work function, the more kinetic energy that checked it electron can possess

Question 4

Bohr model of the atom

Answer 4

States that electron energy levels are stable and discrete corresponding to specific units, and electron can jump from a lower energy to a higher energy or bowl by absorbing a photon of light of the same frequency as the energy distance between the orbits, when an electron falls from a higher energy to low energy orbit it emits a photon of light of the same frequency as the energy difference between the orbits

Question 5

Absorption spectra

Answer 5

Baby impacted by small changes in molecular structure

Question 6

Fluorescence

Answer 6

Occurs when a species absorbs high frequency light and then returns it to its ground state in multiple steps, each step has less energy than the absorbed light and is within the visible range of the electromagnetic spectrum

Question 7

Nuclear binding energy

Answer 7

The amount of energy that is released when nucleons bind together, the more binding energy per nucleon released, the more stable to nucleus

Question 8

Nucleons

Answer 8

Protons and neutrons

Question 9

Four fundamental forces of nature

Answer 9

The strong and weak nucleus force which contribute to the stability of the nucleus, electrostatic forces, and gravitation

Question 10

Mass effect

Answer 10

The difference between the mass of the unbonded nucleons in the mass of the bond of nucleons within the nucleus, the unbounded constituents have more energy and therefore more mass than the bond and constituents, the mass defect is the amount of mass converted to energy during nuclear fusion

Question 11

Fusion

Answer 11

Occurs when small nuclei combine into larger nuclei

Question 12

Fission

Answer 12

Occurs when a large nucleus splits into smaller nuclei

Question 13

Energy in fission and fusion

Answer 13

Energy is released in both fusion and fission because the nuclei formed in both processes are more stable than the starting nuclei

Question 14

Radioactive decay

Answer 14

The loss of small particles from the nucleus

Question 15

Alpha decay

Answer 15

The emission of an alpha particle which is a helium nucleus

Question 16

Beta negative decay

Answer 16

The decay of a neutron into a proton, with the omission of an electron and an anti-neutrino

Question 17

Beta positive decay

Answer 17

Also called positron emission, the decay of a proton into a neutron with a mission of a positron and a neutrino

Question 18

Gamma decay

Answer 18

The emission of a Gamma ray which converts a high energy nucleus into a more stable nucleus

Question 19

Electron capture

Answer 19

The absorption of an electron from the inner shell that combines with a proton in the nucleus to form a neutron

Question 20

Half life

Answer 20

The amount of time required for half of a sample of radioactive nuclei to decay

Question 21

Exponential decay

Answer 21

The rate at which radioactive nuclei decay is proportional to the number of nuclei that remain

Question 22

Energy of a photon of light equation

Answer 22

E = h*f

Question 23

Maximum kinetic energy of an electron in the photoelectric effect equation

Answer 23

Kmax = hf-W

Question 24

Work function equation

Answer 24

W = h*f_t

Question 25

Mass defect and energy equation

Answer 25

E = mc^2

Question 26

Rate of nuclear decay equation

Answer 26

deltan/deltat = -lambda*n

Question 27

Exponential decay equation

Answer 27

n = n_0e^(-lambdat)

Question 28

Decay constant equation

Answer 28

lambda = ln2/T_(1/2) = 0.693/T_(1/2)