types of radiation.

Question 1

why are some isotopes radioactive?

Answer 1

nuclear radiation comes from the nucleus of an atom.
some isotopes are unstable; they may have too many protons or neutrons.
in order that they become more stable the nucleus emits radiation.
this may be in the form of a particle or electromagnetic radiation.
this process is known as radioactive decay.

Question 2

alpha:
symbol:
what it is:
charge:
atomic mass:
speed:
penetration power:
ionising power:

Answer 2

∝
alpha particles are emitted from the nucleus of larger atoms.
2+.
4.
slow.
stopped by paper/ skin. few cm in air.
high.

Question 3

beta:
symbol:
what it is:
charge:
atomic mass:
speed:
penetration power:
ionising power:

Answer 3

β
emitted from the nucleus.
-1.
almost 0.
fast.
stopped by a few mm of aluminium. few m in air.
medium.

Question 4

gamma:
symbol:
what it is:
charge:
atomic mass:
speed:
penetration power:
ionising power:

Answer 4

γ
electromagnetic wave from nucleus.
0.
0.
very fast. speed of light.
reduced by 7 cm of lead. great distances in air.
low.