Radiation

Question 1

(1) Which particle has the same mass as but opposite charge to a β+ particle?

Answer 1

electron

Question 2

(2) Suggest why a beta particle will travel further in air than an alpha particle.

Answer 2

• the ionisation is different
• correct difference in ionisation (1)
• the masses are different (1)
• alpha is bigger than beta (1)
• alpha hits more (air) particles (1)
alpha loses its energy in shorter distance (1)

Question 3

(1) Following the radioactive decay of a nucleus, the nucleus might undergo some rearrangement, losing energy as

Answer 3

gamma radiation

Question 4

(3) Describe the process of β− emission.

Answer 4

• neutron decays / changes
/ becomes (1)
• (neutron) into proton (1)
• (plus an) electron (1)

Question 5

(3) Explain what happens to the mass number and the atomic number of a nucleus when β− emission occurs.

Answer 5

• mass number doesn’t change (1)
• (because) same number of nucleons / quarks (1)
• atomic number goes up by one (1)
• (because) there is an extra proton (1)

Question 6

(1) An isotope above the stability curve will undergo ȕ– decay because it has

Answer 6

too many neutrons

Question 7

(1) Which statement is correct for ȕ+ and ȕ– particles?

Answer 7

a 
\+ is positively charged
and a 
-
is negatively charged

Question 8

(2) Carbon-14 decays by emitting a ȕ–
particle to form an isotope of nitrogen.
Complete the nuclear equation for this decay by filling in the xs

xC^y=xN^y + xB– 1^y

Answer 8

7N^14 + -1B- ^0

Question 9

(2) Describe the arrangement of quarks in a proton.

Answer 9

Up and down (quarks) / Three

quarks) (1

Question 10

(2) Explain what happens to a nucleus during ȕ+ decay

Answer 10

Either
proton changes to a neutron (1)
positron/anti-electron (emitted)
(1)
OR
up quark changes to a down
quark (1)
positron/anti-electron (emitted)
(1)
OR
proton number goes down by
one / neutron number goes up by
one (1)
number of nucleons stays the
same (1)