Nuclear Chemistry Flashcards
What is an isotope?
An atom with the same number of protons but a different number of neutrons.
What is a radioisotope?
An unstable isotope that gives out radiation to become more stable.
What is radioactive decay?
When an unstable nucleus releases radiation and changes into a different element.
What types of radiation can be released?
Alpha particles, beta particles, gamma rays, and sometimes neutrons.
Why do radioisotopes emit radiation?
To rebalance their atomic and mass numbers and become stable.
What is an alpha particle?
Two protons and two neutrons (like a helium nucleus).
What charge does an alpha particle have?
+2 (double positive).
How far can alpha particles travel in air?
Only a few cm — they are stopped quickly.
What absorbs alpha particles?
A sheet of paper.
What attracts alpha particles?
Negatively charged plates (because they’re positive).
What is a beta particle?
A fast-moving electron from the nucleus.
What charge does a beta particle have?
-1
How far can beta particles travel in air?
Over a metre.
What absorbs beta particles?
Aluminium (about 5 mm thick).
: What attracts beta particles?
Positively charged plates (because they’re negative).
What is a gamma ray?
A wave of electromagnetic radiation from the nucleus.
Does gamma radiation have a charge?
No, it has no charge.
What absorbs gamma radiation?
Thick lead or metres of concrete.
How far can gamma radiation travel?
Long distances — it penetrates most materials.
What must be balanced in a nuclear equation?
Mass numbers and atomic numbers on both sides.
What particle is released in alpha decay?
An alpha particle (⁴₂He) — 2 protons, 2 neutrons.
What happens to the atom in alpha decay?
Mass number decreases by 4, atomic number decreases by 2.
What particle is released in beta decay?
A beta particle (⁰₋₁e) — a fast-moving electron.
What happens to the atom in beta decay?
Mass number stays the same, atomic number increases by 1.
