Quantum Number and Nuclear Physics (5/13)

Question 1

Atomic forces

Answer 1

Electromagnetic
Gravitational
Strong nuclear
Weak nuclear

Question 2

Strong nuclear force

Answer 2

Holds protons together in the nucleus (stronger than electromagnetic force)

Question 3

Bond state

Answer 3

lower energy

more stable

Question 4

Mass defect

Answer 4

The different of 0.047 x 10^-27 kg of the expected vs actual mass of nucleus

Question 5

Binding energy

Answer 5

Explains why the mass of the nucleus has a smaller mass combined than the total mass of each individual particle added together

Question 6

Binding energy equation

Answer 6

E=mc^2
speed of light is squared
measured in eV (electron volts)
m=E/c^2

Question 7

Wave particle duality

Answer 7

a property of all matter
wavelength= h/ mass*velocity
6.62x10^-34 is h

Question 8

Heisenberg’s uncertainty principle

Answer 8

says why electrons do not crash into the nucleus due to the attractive force between opposite charges
-electron must be in constant motion

Question 9

Photoelectric effect

Answer 9

when photons hit surface of metal, they excite metallic electrons to higher energy states causing them to move further

Question 10

Work function (phi)

Answer 10

E_kinetic=h*f-phi

phi- energy going in

Question 11

Intensity

Answer 11

corresponds to number of photons

Question 12

Energy of a photon equation

Answer 12

E_photon=KE_electron + Work function

Question 13

Isotopes

Answer 13

atoms with the same number of protons, but different number of neutrons

Question 14

Nuclear reaction

Answer 14

involving nuclear reactions like fusion, fission, nuclear decay, transmutation

Question 15

Fusion

Answer 15

two or more nuclei forced together with very high energy levels
Releases binding energy
A large amount of energy is used to force two or more nuclei together, leading to the formation of a different element

Question 16

Fission

Answer 16

Breaks large nucleus into more nuclei (no particles are lost)
Energy can be harvested by nuclear power plant

Question 17

Radioactive decay

Answer 17

When unstable isotopes break down and eject mass, and energy or photons

Question 18

Alpha decay

Answer 18

Emission of alpha particle which is two protons and two neutrons (also known as helium nucleus)
-decreases by atomic number of 2 and mass of 4

Question 19

Beta decay

Answer 19

-: neutron is converted to a proton and an electron is ejected
atomic number goes up by one, but mass does not change
+: proton is converted into a neutron and a positron is ejected
atomic number goes up by one, but mass does not change
atomic number goes down by one, but mass does not change

Question 20

Electron capture

Answer 20

a nucleus absorbs electron and merges with proton to become an electron
causes atomic number to decrease by one and weight stays same

Question 21

Gamma decay

Answer 21

excited nucleus, high in energy
no mass or charge so no change in either
just change in energy

Question 22

Nuclear reaction overall

Answer 22

nuclear particles are never lose entirely
subtract particles bring lost from parent nucleus
Atomic mass and atomic number are unaffected by gamma

Question 23

Half life

Answer 23

Amount of time for half of the material to decay

Question 24

Half life equation

Answer 24

N=N0(1/2)^t/t_1/2

Question 25

Positron emission tomography

Answer 25

short half life injected into body and undergoes beta-plus decay and helps determine where positrons are emitted