Nuclear Physics

Question 1

The atom

Answer 1

Protons and neutrons are in the nucleus and are referred to as nucleons. They both have equal mass.

Question 2

Proton

Answer 2

Particle in nucleus of atoms with a relative charge of +1

Question 3

Neutron

Answer 3

Particle in nucleus of atoms with a relative charge of 0

Question 4

Electrons

Answer 4

Relative charge of -1

Question 5

If a particle looses electrons

Answer 5

Becomes positively charged

Question 6

If a particle gains electrons

Answer 6

Becomes negatively charged

Question 7

How do we represent nuclei:

Answer 7

A
C
Z
A: mass number or nucleon number = protons+neutrons
Z: atomic number or proton number= protons

Question 8

Isotopes

Answer 8

Atoms of the same element that have the same number of protons and different number of neutrons.

Question 9

Fission

Answer 9

Splitting a bigger nuclei into two smaller ones
-every time there is fission, energy is released

Question 10

Fusion

Answer 10

Two smaller nuclei being joined to form a bigger one
-energy is also released

Question 11

Radioactivity, how is it detected

Answer 11

-using a Geiger counter, measured in counts/s

Question 12

Background radiation

Answer 12

Measures the level of ionizing radiation present in the environment at a specific location.

Question 13

Examples of sources of background radiation

Answer 13

-food and drinks
-cosmic rays
-man made sources

Question 14

Three types of nuclear emission

Answer 14

1) Alpha emission α (very high ionizing power)
2) Beta emission β (intermediate)
3) Gamma emission γ (very low)

Question 15

Alpha emission

Answer 15

Nature: helium nucleus of 2 protons and 2 neutrons
-In nuclear equations mass and charge have to be balanced out.
-deflects upwards

Question 16

Beta emissions

Answer 16

• β- = electron
• deflects downwards
  0 0
  B = e-
  -1 -1
  -In Beta minus emission, a neutron turns into a proton emitting an electron.

Question 17

Gamma emission

Answer 17

0 (no mass)
γ
0 (no charge)
-neutral
-radiation to release excess of energy normally after alpha and beta emissions.
-deflects in a straight (neutral) line

Question 18

Radioactive decay

Answer 18

-emission of ionizing radiation by unstable nuclei
- “decay”: transform into something else by emitting ionizing radiation
-Random and spontaneous
-if a nucleus has too many neutrons it will be unstable.
-Isotopes of elements may be radioactive and emit radiation if they are unstable

Question 19

Half life

Answer 19

Time taken for half the nuclei of a radioactive sample to decay

Question 20

Safety precautions

Answer 20

-protective suits: absorb radiation
-radioactive hazard labels: warn people about danger to stay safe
-…