The document discusses counting particles in atomic nuclei and describing radioactive decay. It provides examples of carbon-14 and carbon-12 isotopes and asks the reader to count the protons and neutrons in each. It also discusses alpha and beta decay and asks the reader to write nuclear equations showing how each type of decay changes the nucleus.

1. COUNTING THE PARTICLES
L.I.
•To describe the nucleus
•To use nuclear equations to work out
what happens during radioactive decay.
Keywords:
•Isotopes
•Protons and neutrons
•α and β particles

2. Revision:
The nucleus of an atom is described by
mass number and atomic/proton number.
The number of particles in the
C C
14 12
nucleus (protons + neutrons)
6 6
This is the number of protons
To do:
Count the number of particles inside the nuclei of these carbon isotopes.
Carbon-14 isotope
Number of protons = _________
Number of neutrons = _________
Carbon-12 isotope
Number of protons = _________
Number of neutrons = _________

3. How does alpha decay change the nucleus?
To do: Write a nuclear equation for this decay.

4. During a beta decay, A neutron in
the nucleus decays to a proton
and an electron (β particle).
How does beta decay change the nucleus?

5. How does beta decay change the nucleus?
To do: Write a nuclear equation for this decay.

6. QUESTIONS

7. EXTENSION QUESTION
Nuclear fission