Atomic Phenomenon

Question 1

Photoelectric effect

Answer 1

The ejection of an electron from the surface of a metal in response to light.

Question 2

Threshold frequency

Answer 2

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

1) The work function is the minimum energy necessary to eject an electron in a given metal. Its value depends on the metal used and can be calculated by multiplying by Plank’s constant

E = energy of the photon of light
h = Planck’s constant
f = frequency of the light

Question 3

Bohr model of atom

Answer 3

States that electron energy levels are stable and discrete, corresponding to specific orbitals.

1) An electron can jump from a lower-energy orbital to a higher energy orbit by absorbing a photon of light at the same frequency as the energy difference between orbitals.

2) When an electron falls to a lower energy level, it emits a photon of light at the same frequency of the difference in energy levels.

Question 4

Absorption spectra

Answer 4

May be impacted by small changes in molecular structure

Question 5

Fluorescence

Answer 5

When a species absorbs high-frequency light and then returns to its ground state in multiple steps. Each step has less energy than the absorbed light and is within the visible range electromagnetic spectrum.

Question 6

Nuclear binding energy

Answer 6

The amount of energy released when nucleons (protons and neutrons) bind together.

1) The more binding energy released, the more stable the nucleus.

Question 7

Four fundamental forces of nature?

Answer 7

1) Strong nuclear force
2) Weak nuclear force
3) Gravitational force
4) Electromagnetic force

Question 8

Strong and weak nuclear force

Answer 8

Contribute to the stability of the nucleus, electrostatic forces, and gravitation.

Question 9

Mass defect

Answer 9

The difference between the mass of the unbounded nucleons and the mass of the bonded nucleons within the nucleus.

1) Unbonded protons and neutrons have more energy
2) mass defect is the amount of mass converted to energy during nuclear fusion

Question 10

Fusion

Answer 10

Occurs when small nuclei combine into larger nuclei

Question 11

Fission

Answer 11

Occurs when large nucleus splits into smaller nucleus

Question 12

Radioactive decay
(Types)

Answer 12

Loss of small particles from the nucleus.

Types:
1) Alpha decay
2) Beta-negative decay
3) Beta-positive decay
4) Gamma decay
5) Electron capture

Question 13

Alpha decay

Answer 13

The emission of an alpha particle, which is a helium nucleus, which consists of 2 protons, 2 neutrons, and 2 electrons

alpha particles don’t have electrons, so they have a charge of +2

Question 14

Beta-negative decay

Answer 14

The decay of a neutron into a proton, with emission of an electron (e-, β-) and an antineutrino (v). a neutron is converted into a proton and a β- particle

In beta decay there needs to be a conservation of charge. If a negative charge (β-) is created, a neutron is converted into a proton to maintain charge.

Question 15

Beta-positive decay

Answer 15

Also called proton emission, is the decay of a proton into a neutron, with emission of a positron (e+, β+) and a neutrino (v). a proton is converted into a neutron and a β+ particle

In beta decay there needs to be a conservation of charge. If a positive charge (β+) is created, a proton is converted into a neutron to maintain charge.

Question 16

Gamma decay

Answer 16

The emission of a gamma ray, which converts a high energy nucleus into a more stable form
no change in mass number or atomic number, only a γ-ray is emitted

Question 17

Electron capture

Answer 17

The absorption of an electron from the inner shell that combines with a proton in the nucleus to form a neutron. atomic number is now one less, but the mass number stays the same

Question 18

Half-life

Answer 18

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

Question 19

Exponential decay

Answer 19

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