Chapter 9 - Atomic and Nuclear Phenomena

Question 1

Photoelectric effect

Answer 1

Light of a sufficiently high frequency incident on a metal and a vacuum causes metal to emit electrons

Question 2

Threshold frequency

Answer 2

Minimum frequency of light that causes ejection of electrons

Question 3

Photons

Answer 3

Light quanta

Question 4

Work function

Answer 4

Minimum energy required to eject an electron

Question 5

Absorption of light

Answer 5

Electron jumps from lower to higher energy orbit by absorbing photon

Question 6

Emission of light

Answer 6

Electron falls from higher to lower energy orbit by emitting photon

Question 7

Fluorescence

Answer 7

Process in which the electrons of certain substances are excited to higher - energy levels by high frequency photons, and then emit visible light as the energy is released in two or more steps back to ground state

Question 8

Mass defect

Answer 8

Difference between the sum of the masses of unbound nucleons forming a nucleus and the mass of that nucleus in the bound state

Question 9

Strong nuclear force

Answer 9

Responsible for the binding of protons and neutrons together in nucleus

Question 10

Weak nuclear force

Answer 10

Responsible for radioactive decay and contributes to nuclear stability

Question 11

Binding energy

Answer 11

Allows nucleons to bond

Question 12

Nuclear reactions

Answer 12

Involve either combining or splitting the nuclei of atoms

Question 13

Fusion

Answer 13

Small nuclei combined to form larger nucleus

Question 14

Fission

Answer 14

Large nucleus splits into smaller nuclei

Question 15

Radioactive decay

Answer 15

Spontaneous decay of certain nuclei accompanied by emission of particles

Question 16

Alpha decay

Answer 16

Emission of alpha particle
Atomic = -2
Mass= -4

Question 17

Beta negative decay

Answer 17

Decay of a neutron into a proton Atomic = +1
Mass=no change

Question 18

Beta positive decay (positron)

Answer 18

Decay of a proton into a neutron
Atomic = -1
Mass = no change

Question 19

Gamma decay

Answer 19

Emission of gamma rays
- no change to mass or atomic

Question 20

Electron capture

Answer 20

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

Question 21

Half-life

Answer 21

Time it takes for half of sample to decay

Question 22

Exponential decay

Answer 22

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