Nuclear Reactions

Question 1

atomic number

Answer 1

• number of protons in the nucleus

- used to identify the element

Question 2

mass number

Answer 2

• number of protons plus neutrons

- used to identify the isotope of the element

Question 3

isotope

Answer 3

same number of protons but different number of neutrons/ same atomic number but different mass number
isotopes of an element have similar chemical properties but undergo different nuclear reactions.

Question 4

what is emitted in alpha decay?

Answer 4

two protons and two neutrons (helium nucleus)

Question 5

what happens to atomic and mass number after alpha decay?

Answer 5

• mass number decreases by 4

- atomic number decreases by 2

Question 6

when does beta decay occur?

Answer 6

when a neutron decays into a proton and an electron which is emitted from the nucelus

Question 7

what happens to atomic and mass number after beta decay?

Answer 7

• mass number unchanged

- atomic number increases by 1

Question 8

what is emitted in gamma decay?

Answer 8

isotopes emit a high-energy photon of electromagnetic radiation

Question 9

what happens to atomic and mass number after gamma decay?

Answer 9

gamma emission does not affect the atomic number or mass number.

Question 10

symbol for proton (read AZX)

Answer 10

1 1 P

Question 11

symbol for neutron (read AZX)

Answer 11

1 0 n

Question 12

symbol for electron (read AZX)

Answer 12

0 -1 e

Question 13

symbol for alpha (read AZX)

Answer 13

4 2 He

Question 14

symbol for beta (read AZX)

Answer 14

0 -1 e

Question 15

what are the two types of nuclear fission?

Answer 15

spontaneous and induced

Question 16

spontaneous fission

Answer 16

natural process in which a larger nucleus splits into two smaller nuclei
also releases neutrons

Question 17

induced fission

Answer 17

nucleus bombarded by a neutron and then becomes unstable

separates into two nuclei and emits neutrons which can then bombard other nuclei (chain reaction)

Question 18

nuclear fusion

Answer 18

process in which two nuclei combine to form a nucleus of larger mass number

Question 19

the sun uses…

Answer 19

fusion to generate energy

Question 20

what isotopes of hydrogen combine to form helium in nuclear fusion?

Answer 20

deuterium and tritium

Question 21

equivalence of mass and energy

Answer 21

in all nuclear reactions the mass before is greater than the mass after
this is because some of the original mass has been converted into energy
E=mc^2

Question 22

fusion reactors

Answer 22

require charged particles at a very high temperature which have to be contained by magnetic fields

Question 23

approximate temperature of fusion reactors?

Answer 23

10 million kelvin

Question 24

problem of high temperature in fusion reactors?

Answer 24

• produces a plasma that needs to be contained inside the reactor vessel.
• this is done using a very powerful magnetic field produced by electromagnets
• great deal of power required to maintain the electromagnets.
• hot enough to melt/evaporate walls of reactor.

Question 25

what is a further issue with fusion reactors?

Answer 25

once a reactor is up and running, there are further issues with extracting energy from the plasma as the reactor continues to run.