Nuclear fission and nuclear fusion

Question 1

During the process of nuclear fission atomic nuclei

Answer 1

Split

Question 2

Nuclear fission releases …

what can it be used for.

Answer 2

This process releases energy, which can be used to heatwater and turn it into steam. The steam drives a turbine, which is connected to a generator and generates
electricity.

Question 3

Nuclear fusion is the joining together of atomic ..

Its the process by which energy is released in .

Answer 3

nuclei

stars

Question 4

There are two fissionable substances in common

use in nuclear reactors which are

Answer 4

uranium-235 and

plutonium-239.

Question 5

For fission to occur the uranium-235 or

plutonium-239 nucleus

Answer 5

must first absorb a neutron.

Question 6

The nucleus undergoing fission splits into

Answer 6

two smaller nuclei and two or three neutrons and

energy is released.

Question 7

The neutrons in fission may go on to start

Answer 7

a chain reaction.

Question 8

Nuclear fusion is

Answer 8

the joining of two atomic nuclei

to form a larger one.

Question 9

Nuclear fusion is the process by which

Answer 9

energy is released from stars

Question 10

Stars form when

Answer 10

enough dust and gas from space is pulled together by gravitational attraction

Question 11

explain why the early Universe contained only hydrogen but now contains a large variety of different elements.

Answer 11

formed due to a collapse of a massive star and then the explosion of a supernova. the elements are the debris of the explosion.

Question 12

During the ‘main sequence’ period of stars life cycle a star is stable

Answer 12

because the forces within it are balanced.

Question 13

Life cycle of star is determined by its

Answer 13

size

Question 14

explain the life cycle of a star that is about the same size as the Sun

Answer 14

protostar-main sequence star-red giant- white dwarf-black dwarf

Question 15

explain the life cycle of a star that is much bigger than the Sun

Answer 15

protostar-main sequence star-red super giant-super nova- either a neutron star or black hole

Question 16

Fusion processes in stars produce all of the

Answer 16

naturally occurring elements

Question 17

explain how stars are able to maintain their energy output for millions of years.

Answer 17

the forces within the star are balanced. the force of gravity contracting is balanced by the outward force of radiation.

Question 18

elements up to iron are formed during the

Answer 18

stable period

Question 19

Elements heavier than iron are formed in a

Answer 19

supernova