Isotopes & Radioactivity Slide Show #2

What are isotopes? Atoms that differ in the number of neutrons. All of these isotopes have the same number of protons and the same number of electrons.

Hydrogen’s Isotopes

Atomic Mass The presence of isotopes is why atomic mass is in decimal form. Atomic mass is Average Atomic Mass E.g. Hydrogen's atomic mass is not one. The mass is actually a.m.u. (atomic mass units). The takes into account the isotopes of hydrogen.

Isotopes bond the same as regular atoms do! Because their electrons stay the same. They have capability of bonding covalently or ionically depending on whether they are metals or non-metals.

Radioactivity When an atom is radioactive, the nucleus is unstable. (more neutrons than protons) Nuclear particles are released along with energy. This is called Radioactive Decay.

Alpha Particles Alpha particles consist of 2 protons and 2 neutrons. That atom is no longer that atom! It is a different element.

Another example of alpha decay

Beta Decay In Beta Decay, an electron is released (Beta Particle) A proton is gained. It becomes an element with the next highest number. This is called transmutation.

Uses of Radioactive Decay Medical uses Image of bloodstream (Iron—59) Treatment of Brain Tumors (Cobalt-60) Can kill bacteria in food.

Half-Life Isotopes decay at very different rates. Some decay happens in a matter of days, minutes, seconds, or even take millions of years. Half-life is the time it takes for a sample of a radioactive isotope to decay to half its original mass. Uranium-235 has a half life of 713 million years.

Synthetic elements Radioactive elements made in the lab. Scientists use particle accelerators to speed up reactions to make synthetic elements.