twelfth paper

Question 1

how many types of radioactivity did ruthford discover?

Answer 1

3

Question 2

the 3 types of radioactivity and what they are made of

Answer 2

1) alpha particles - is a helium nucleus
2) beta particles - is a high energy electron
3) gamma ray - is a electromagnetic radiation with a very short wavelength

Question 3

radiation passing though a magnetic field shows what three things?

Answer 3

1) massive positive alpha particles are deflected one way
2) less massive negative beta particles are deflected the opposite direction
3) gamma rays are not deflected

Question 4

define radioactivity

Answer 4

the spontaneous emission of particles or energy from an atomic nucleus as it disintegrates

Question 5

define radioactivity decay

Answer 5

the spontaneous disintegration of a nucleus

Question 6

how do massive nuclei gain stability?

Answer 6

by breaking into smaller nuclei with a release of energy

Question 7

how do smaller nuclei gain stability?

Answer 7

by joining together with the release of energy

Question 8

what are the protons and neutrons that occur in the nucleus called?

Answer 8

nucleons

Question 9

in the nucleus, what does the nuclear force dominate?

Answer 9

the repulsive coulomb force between positive protons and holds the nucleus together

Question 10

the number of protons is the atomic number which determines the…

Answer 10

identity of an element

Question 11

the number of protons and neutrons determines the…

Answer 11

atomic mass of an element

Question 12

different isotopes of an elements have the same ___ ___ but different ___ ____

Answer 12

atomic number
atomic masses

Question 13

radioactive decay produces a simpler and more stable _____

Answer 13

nucleus

Question 14

nuclear reactions must balance like ___ ___

Answer 14

chemical reactions

Question 15

the half life of a radioactive substance is the time it takes for ….

Answer 15

half of the nuclei to decay

Question 16

half lives can be how long?

Answer 16

seconds - billions of years

Question 17

alpha particles are emitted with ____ energy

Answer 17

high

Question 18

penetrating powers of
alpha particle
beta particle
gamma ray

Answer 18

can barely penetrate through a piece of paper
can penetrate a few mm of aluminium
can penetrate several cms of lead

Question 19

what is carbon dating?

Answer 19

a process thats used to determine how long ago an organism died.

Question 20

a type of radiation that isnt harmful

Answer 20

radiowaves

Question 21

what is ionizing radiation

Answer 21

particles or waves that have enough energy to ionize atoms. can damage and kill living things

Question 22

radiation can ____ chemical bonds in biological macromolecules such as ___

Answer 22

disrupt
dna

Question 23

mass of any nucleus is less than…

Answer 23

the sum of the masses of the individual constituent nucleons which make it up

Question 24

the loss of mass which results whn nucleons form a nucleus is attributed to…

Answer 24

a binding energy, and is a measure of the strength of the strong nuclear force holding the nucleons together

Question 25

how can binding energy be calculated?

Answer 25

Einsteins equivalence of mass and energy

Question 26

in order to seperate the nucleons, binding energy must be supplied to the _____

Answer 26

nucleus

Question 27

how do you supply binding energy to the nucleus?

Answer 27

by bombarding the nucleus with high energy particles

Question 28

define nuclear fission

Answer 28

when a heavy nucleus splits apart into two smaller nuclei

Question 29

define fusion:

Answer 29

when two light nuclei fuse into one nucleus, energy is released

Question 30

nuclear fusion is the source of the _____ from the sun and stars

Answer 30

energy