Atomic Symbols and Isotopes mass # K 39 19 neutrons + protons element Symbol atomic # protons # protons = # of electrons for a NEUTRAL atom 39 - 19 = 20 n0 How many neutrons are present? How many electrons are present? 19 e-

Complete the Table Below Name Symbol Protons Neutrons Atomic Number Mass Number Carbon-14 6 8 14 Potassium-41 19 22 41 Lead-206 82 124 206

Unstable Nucleus = Radioactive Radioactivity What is radioactivity? Radioactivity occurs when an unstable nucleus spontaneously emits fragments of the nucleus and/or energy. Unstable Nucleus = Radioactive Why are only some isotopes radioactive? The ratio of protons to neutrons in the nucleus determines whether or not a nucleus is radioactive.

Depicting Nuclear Reaction For nuclear reactions, the sum of the mass numbers (top numbers) and the sum of the atomic numbers (bottom number) must be the same on both sides. Mass Numbers: 9 + 4 = 12 + 1 13 = 13  Atomic Numbers: 4 + 2 = 6 + 0 6 = 6 

Finding the Missing Nucleus Mass Numbers 234 = 4 + ? ? = 230 Atomic Numbers 90 = 2 + ? ? = 88

Finding the Missing Nucleus Mass Numbers 14 = 0 + A A = 14 Atomic Numbers 6 = -1 + Z Z = 7

Examples of Transmutation Reactions These are all transmutation reactions because the elements on the left side are changed to produce a different element on the right side.

Emissions from Radioisotopes Type of Particle Emitted Description Symbol Mass Charge Why is it Emitted? Alpha A Helium Nucleus 4 amu +2 Nucleus is too large. Beta A Fast Moving Electron -1 Too many neutrons Gamma Electromagnetic Radiation 0 amu Too much energy A radioisotope is a nucleus that is radioactive or unstable.

Writing Nuclear Decay Equations Write the nuclear decay equation for the alpha decay of uranium-238. Write the symbol for the type of decay. Start your decay equation by writing the symbol for this nucleus and then follow it with an arrow. Mass Number: 238 = 4 + ? ? = 234 Atomic Number: 92 = 2 + ? ? = 90

Writing Nuclear Decay Equations Write the nuclear decay equation for the beta decay of iodine-131. Write the symbol for the type of decay. Start your decay equation by writing the symbol for this nucleus and then follow it with an arrow. Mass Number: 131 = 0 + ? ? = 131 Atomic Number: 53 = -1 + ? ? = 54

Writing Nuclear Decay Equations Write the nuclear decay equation the emission of a gamma ray from carbon-14. Start your decay equation by writing the symbol for this nucleus and then follow it with an arrow. Write the symbol for the type of decay. Mass Number: 14 = 0 + ? ? = 14 Atomic Number: 6 = 0 + ? ? = 6

Examples of Transmutation Reactions These are all transmutation reactions because the elements on the left side are changed to produce a different element on the right side.

Decay Series for Uranium-238 This diagram shows the steps that an isotope of uranium takes to reach a stable isotope, lead-206.

A Closer Look at the Decay Series Write a nuclear decay equation for what we occur to uranium-234 according to this decay series.

A Closer Look at the Decay Series Write a nuclear decay equation for what we occur to lead-210 according to this decay series.

Writing Nuclear Decay Equations Write the nuclear decay equation for the alpha decay of uranium-238. Write the symbol for the type of decay. Start your decay equation by writing the symbol for this nucleus and then follow it with an arrow. Mass Number: 238 = 4 + ? ? = 234 Atomic Number: 92 = 2 + ? ? = 90

Writing Nuclear Decay Equations Write the nuclear decay equation for the beta decay of iodine-131. Write the symbol for the type of decay. Start your decay equation by writing the symbol for this nucleus and then follow it with an arrow. Mass Number: 131 = 0 + ? ? = 131 Atomic Number: 53 = -1 + ? ? = 54

Writing Nuclear Decay Equations Write the nuclear decay equation the emission of a gamma ray from carbon-14. Start your decay equation by writing the symbol for this nucleus and then follow it with an arrow. Write the symbol for the type of decay. Mass Number: 14 = 0 + ? ? = 14 Atomic Number: 6 = 0 + ? ? = 6

Protecting Ourselves from Radioactive Particles

Positive Uses of Nuclear Chemistry Nuclear Power Nuclear Medicine Kills Bacteria on Food