Isotopes And Nuclear Radiation

Question 1

what kind of ‘atoms’ tend to decay and why

Answer 1

unstable isotopes decay into other elements to become more stable

Question 2

how many isotopes of an element are originally stable

Answer 2

one or two

Question 3

what do radioactive substances do when decaying

Answer 3

they spit out one or more types of ionising radiation from their nucleus

Question 4

what are the three common types of ionising radiation spit out of a nucleus during decay

Answer 4

gamma, beta and alpha radiation

Question 5

other than ionising radiation, what can decaying isotopes also release and why

Answer 5

• neutrons from their nucleus

- to rebalance their atomic and mass numbers

Question 6

what is ionising radiation

Answer 6

radiation that knocks electrons off atoms

Question 7

what does ionising radiation usually turn an atom into if it is hit by one

Answer 7

a positively charged ion

Question 8

what is alpha radiation

Answer 8

when an alpha particle is emitted from the nucleus

Question 9

what is an alpha particle

Answer 9

more or less an isotope of a helium nucleus, consisting of two protons and neutrons

Question 10

what are some of the characteristics of alpha particles

Answer 10

• dont penetrate very far into materials and are stopped quickly
• can only travel a few cm in the air
• absorbed by a sheet of paper
• have a charge of 2+

Question 11

what is a beta particle

Answer 11

a fast moving electron released by a nucleus

Question 12

what are some of the characteristics of a beta particle

Answer 12

• virtually no mass
• charge of -1
• moderately ionising
• penetrate moderately far into materials before colliding
• travel a few meters in the air
• absorbed by a sheet of aluminium (5mm)`

Question 13

what is the effect of a beta minus particle being emitted out of a nucleus

Answer 13

a neutron in the nucleus turns into a proton and electron

Question 14

what are gamma rays

Answer 14

waves of electromagnetic radiation released by the nucleus

Question 15

what are the characteristics of gamma rays

Answer 15

• penetrate far into materials
• travel a long distance through air
• weakly ionising
• absorbed by thick sheets of lead or meters of concrete

Question 16

why are gamma rays weakly ionising

Answer 16

because they tend to pass through things rather than collide with atoms, but they’ll eventually hit something and do some damage

Question 17

what is alpha radiation used in and how does it work

Answer 17

• used in smoke detectors
• ionises air particles causing a current flow
• if smoke is in the air, it binds to the ions
• binding means the current stops and the alarm sounds

Question 18

what are beta emitters used for and why

Answer 18

• testing the thickness of sheets of metal
• used as the particles are not immediately absorbed by the material like alpha radiation
• the dont penetrate as far as gamma rays