Download Radioactivity Revision Questions Decay – Nucleus

Radioactivity
Revision Questions
Decay – Nucleus - Isotope
1. What is Radioactivity?
Sometimes the nucleus of an atom is unstable. A change will occur in the nucleus to
make it more stable. The change is called a decay
2. During Radioactive Decay, what can a Nucleus Emit?
When a nucleus decays it will emit (give out) some particles or waves. Emitting
particles or waves from the nucleus is called radioactivity.
3. Is Radioactive Decay a Random Process?
Radioactive decay is a random process which gives out heat.
4. What are the Three Types of Radioactivity called?
There are three types of radioactivity, called alpha, beta and gamma.
A radioactive nucleus will emit either an alpha particle or a beta particle or a gamma
ray. After an alpha particle or a beta particle has been emitted from a nucleus,
the atomic number of the atom will have changed. The atom will have changed into
a different element. An alpha or beta emitter might also emit gamma radiation.
5. What does the Nucleus of an Atom contain?
The nucleus of an atom contains protons and neutrons. Protons are
all positively charged and repel each other. The protons in the nucleus are held
together by a
force called the strong nuclear force (or strong interaction).
6. What is the Atomic Number?
Protons and neutrons are sometimes called nucleons.
The number of protons is called the atomic number.
7. What is the Mass Number?
The number of protons plus neutrons is called the mass number.
The mass number is sometimes called the nucleon number.
8. What is an Isotope?
Isotopes of an element can exist where the atoms have different numbers
of neutrons.
Cambridge international school
IGCSE physics
9. How can a Nucleus Be Unstable?
A stable atom will have a stable number of neutrons.
For small atoms (containing less than 20 protons) a stable atom will have
approximately the same number of protons and neutrons.
An atom which is very different from this will be unstable.
10. How can an Unstable Nucleus change into a More Stable form?
The unstable nucleus will decay and emit radioactivity.
Radioactive nuclei are also called radioactive isotopes,
radioisotopes and radionuclides (they all mean the same thing).
After the decay, the nucleus will have changed into a
more stable form. The atomic number will have changed
and a new element is formed
11. What is a Radionuclide?
The unstable nucleus will decay and emit radioactivity.
Radioactive nuclei are also called radioactive isotopes,
radioisotopes and radionuclides
Cambridge international school
IGCSE physics