Isotopes

Fukushima disaster May 11, 2011 Fukushima nuclear power plant damaged by tsunami

Chernobyl Disaster April 26, 1986 Melt down inside the reactor in Unit #4 of the Chernobyl Nuclear Power Plant The steam explosion and fire blew the 1000-ton roof off the building and allowed radioactive material to escape (Cs-137, I-131, and Sr-90)

Thyroid cancer Radioactive iodine deposited in pastures  eaten by cows  cow milk drunk by children Radioactive iodine to accumulated in the thyroid Thyroid produces hormones that regulate your heart rate, blood pressure, body temperature and weight

Nuclear power Nuclear fission = Process of splitting atoms Fission produces free neutrons and protons and release large amount of energy Marble demo

Isotopes Isotopes = have nucleus with the same number of protons but different number of neutrons Therefore, isotopes have different mass numbers Unstable atoms are radioactive, nucleus can decay or change by emitting radiation

Average atomic mass Average atomic mass of an atom is found by averaging the natural abundance of its isotopes E.g. 35/17 Cl (75%) and 37/17 Cl (25%) (0.75 x 35) + (0.25 x 37) = 35.5 amu