Topic 7 - Radioactivity

Question 1

what is the nucleus of an atom?

Answer 1

the centre of an atom containing protons and neutrons. it contains most of the atom’s mass.

Question 2

what is the atomic number?

Answer 2

the number of protons in the nucleus

Question 3

what is the mass number?

Answer 3

total number of protons and neutrons

Question 4

what gives an atom its overall size?

Answer 4

the paths of electrons

Question 5

are atoms charged?

Answer 5

no, they are neutral. the number of protons = the number of electrons

Question 6

what is an isotope?

Answer 6

isotopes are atoms with the same number of protons but a different number of neutrons

Question 7

what are the two types of isotope?

Answer 7

stable and unstable

Question 8

what happens in unstable isotopes?

Answer 8

the nucleus breaks down and emits radiation

Question 9

how do the nuclei of unstable isotopes break down?

Answer 9

randomly

Question 10

is it possible to predict when a single nuclei is going to decay?

Answer 10

no

Question 11

is it possible to make a decay happen?

Answer 11

no

Question 12

is radioactive decay affected by physical conditions?

Answer 12

no

Question 13

what is created when a nucleus decays?

Answer 13

one or more type of radiation

Question 14

what are the types of radiation?

Answer 14

alpha, beta, and gamma

Question 15

where is background radiation present?

Answer 15

everywhere, all the time

Question 16

what are sources of background radiation?

Answer 16

1. substances on earth - air, food, building materials, soil, rocks
2. radiation from space
3. living things
4. radiation from human activity