Radioactive Decay

Uranium-238  decays into  Thorium-234  by emitting .........

• an alpha particle
• a beta particle
• gamma rays
• visible light

Which type of nuclear radiation is being emitted here?

• Alpha
• beta
• gamma 
• none

A helium nucleus with two protons and two neutrons is called a(n) ____.  

• alpha particle
• electroscope
• beta particle
• gamma ray

Gamma rays have

• no mass

• a huge mass

• a small mass

• an average mass

The nucleus is held together by the ___________________________force.

• The Strong Nuclear Force

• The Weak Nuclear Force

• Electromagnetism

• Gravity

Radioactive materials have unstable...

• electrons
• protons
• nuclei
• neutrons

What two subatomic particles are found in an atom's nucleus?

• Protons and neutrons

• neutrons and electrons

• electrons and protons

What is likely to happen to unstable nuclei with too many, or too few, neutrons?

• They will decay by emitting radiation.

• They will lose all their electrons.

• They will bond with other atoms.

Describe the structure of an alpha particle.

• a fast-moving electron

• 2 protons and 2 neutrons

• a slow-moving neutron

• a hydrogen nucleus

In alpha decay, the mass number...

• increases by 2

• decreases by 2

• increases by 4

• decreases by 4