Presentation on theme: "Alpha, Beta, and Gamma Decay"— Presentation transcript:
1Alpha, Beta, and Gamma Decay Nuclear ReactionsAlpha, Beta, and Gamma Decay
2State what is meant by alpha, beta and gamma decay of radionuclides. Identify the processes occurring in nuclear reactions written in symbolic form.
3The Atom The atom consists of two parts: 1. The nucleus which contains:protonsneutrons2. Orbiting electrons.
4The AtomAll matter is made up of elements (e.g. carbon, hydrogen, etc.).The smallest part of an element is called an atom.Atom of different elements contain different numbers of protons.The mass of an atom is almost entirely due to the number of protons and neutrons.
5X A Z Mass number = number of protons + number of neutrons Element symbolZAtomic number= number of protons
6X A Z A = number of protons + number of neutrons Z = number of protons A – Z = number of neutronsNumber of neutrons = Mass Number – Atomic Number
7U U 235 92 238 92 There are many types of uranium: A Z Number of protonsNumber of neutronsAZNumber of protonsNumber of neutrons
8U U 235 92 238 92 There are many types of uranium: A 235 Z 92 Number of protonsNumber of neutrons143A238Z92Number of protonsNumber of neutrons146Isotopes of any particular element contain the same number of protons, but different numbers of neutrons.
9Most of the isotopes which occur naturally are stable. A few naturally occurring isotopes and all of the man-made isotopes are unstable.Unstable isotopes can become stable by releasing different types of particles.This process is called radioactive decay and the elements which undergo this process are called radioisotopes/radionuclides.
10Radioactive Decay Radioactive decay results in the emission of either: an alpha particle (a),a beta particle (b),or a gamma ray(g).
11Alpha DecayAn alpha particle is identical to that of a helium nucleus.It contains two protons and two neutrons.
12X Y + He Alpha Decay A Z A - 4 Z - 2 4 2 unstable atom alpha particle more stable atom
33Gamma DecayGamma rays are not charged particles like a and b particles.Gamma rays are electromagnetic radiation with high frequency.When atoms decay by emitting a or b particles to form a new atom, the nuclei of the new atom formed may still have too much energy to be completely stable.This excess energy is emitted as gamma rays (gamma ray photons have energies of ~ 1 x J).