STAAR Ladder to Success Rung 7

– Alpha particles are helium nuclei with low penetrating power; they can be shielded by paper or cloth. – Beta particles are electrons with moderate penetrating power; they can be shielded by heavy aluminum foil. – Gamma radiation is a form of high-energy electromagnetic radiation; it has very high penetrating power and is shielded incompletely by thick layers of lead or concrete.

An alpha particle is identical to that of a helium nucleus. It contains two protons and two neutrons. Occurs when a nucleus loses an alpha particle (a helium nucleus) to become more stable. Alpha decay

X A Z Y A - 4 Z He 4 2 Ra Rn He 4 2 Writing the equation

Beta Decay Occurs when a nucleus loses a beta particle, which is nothing more than an electron Po  0 At

X A Z Y A Z  0 Po Rn  0 Writing the equation

Gamma emission When a nucleus gives of an energetic photon of light called a gamma ray. The mass nor the symbol changes- the resulting nucleus has less energy.

F ission splitting a nucleus into two or more smaller nuclei Produces a great deal of energy Utilized in nuclear reactors and atomic bombs

Fusion combining of two nuclei to form one nucleus of larger mass Produces more energy than nuclear fission Occurs in stars and in thermonuclear weapons (“hydrogen bombs”)