Please answer the question on the board. Good Morning Minions Please answer the question on the board.

Nonmetals Properties Physical Poor conductors of heat and electricity Reactive with other elements Solid nonmetals are dull and brittle Physical 10 of 16 nonmetals are gasses at room temperature Bromine is the only liquid at room temperature Dull, brittle (not malleable), poor conductors

Nonmetals Chemical Properties Reactive with other elements Fluorine is the “most reactive element known” Group 18 rarely ever form compounds

The “Families” Carbon Family Carbon, Silicon, Germanium, Tin, Lead Gain, lose, or share 4 electrons when reacting with other elements Crude oil is made of carbon chains up to 50 carbon atoms!

The “Families” Nitrogen Family Nitrogen, Phosphorus, Arsenic, Antimony, Bismuth Gain or share 3 electrons when reacting with other elements

The “Families” Oxygen Family Group 16: Oxygen, Sulfur, Selenium, Tellurium, Polonium Gain or share two electrons when reacting with another element Oxygen is highly reactive as it can combine with most elements

The “Families” The Halogen Family Fluorine, Chlorine, Bromine, Iodine, Astatine Gains or shares one electron when reacting with other elements Halogen- “Salt Forming” All are VERY reactive and when uncombined are VERY dangerous to humans Fluorine so reactive it reacts to almost everything Water and powdered glass will burn in Fluorine! Very useful! Salts Nonstick coating on pans Help prevent tooth decay Kill bacteria in our swimming pools

Metaloids Boron (B) Silicon (Si) Germanium (Ge) Arsenic (As) Antimony (Sb) Tellurium (Te) Polonium (Po) Astatine (At)

Metaloids What is it? Has some of the characteristics of metals and nonmetals Brittle Hard Somewhat reactive Most common is Silicon (Si) Most useful property is their varying ability to conduct electricity Make semiconductors (Substances that conduct electricity under some circumstances, but not under others.) Ex: Computer chips, transistors, lasers.

Clarification… Atomic Mass Valence Electron Atomic Number Mass of the atom. Proton + Neutron = Atomic Mass Valence Electron How many electrons on the outer-most layer/shell of the electron cloud. Can be from 1 - 8 electrons. Atomic Number The same as the atom’s number of protons.

Pattern evolves!!! You can tell the valence electrons by which group they are in!!! Group 1 = 1 valence electron Group 2 = 2 valence electrons Group 13 = 3 valence electrons Group 14 = 4 valence electrons Group 15 = 5 valence electrons Group 16 = 6 valence electrons Group 17 = 7 valence electrons Group 18 = 8 valence electrons (most stable)

Wait!!! What about groups 3 – 12? Most of the time they have 2 valence electrons… BUT… They can also have 3… (Chromium can have 1!) So for the time being, it is less confusing at this point to say that the transition metals (groups 3-12) can vary. But Groups 1, 2, 13 – 18 all have definite valence numbers!

Question… What do you know about radioactivity?

A little history… 1896 Henri Becquerel Discovered radioactive decay Exposure to photo plate Emission called “Radioactivity” Worked with Marie and Pierre Curie

Types of radioactive decay… Three major forms of natural radioactive decay of an unstable nucleus Alpha decay Beta decay Gamma decay The particles and energy produced during radioactive decay are forms of nuclear radiation

Alpha Decay… Alpha Particle 2 Protons & 2 Neutrons Positive charge Like a Helium Nucleus Lose 4 AMU’s and 2 Protons Creates a new element!

Example… Beryllium-8 (unstable isotope of Beryllium) Loses an alpha particle 8amu – 4amu = 4 amu Beryllium = 4 protons Lose 2 Protons leaving 2 protons Helium = 2 protons Now becomes Helium

Beta Decay Some atoms unstable from too many neutrons Beta Decay Neutron → Proton & Negative charged Beta Particle Beta Particle Fast moving electron given off of nucleus during decay Result 1 less neutron 1 more proton New element!!!

Example… Carbon-14 Nucleus Carbon -14 = 6 protons + 8 neutrons Beta Decay -1 neutron +1 proton & beta particle Nitrogen-14 = 7 protons + 7 neutrons

Gamma Decay Gamma radiation No loss to protons, neutrons, or electrons Has no charge Given off during Alpha & Beta Decay

What can stop radiation? Alpha = small burn Beta = damage cells Gamma = Massive cell damage

Radioactive Isotopes Many uses in science & industry Power Plants ENERGY!!! Tracing chemical reactions Scientists see how plants use phosphorus Tracing industrial processes Find weak spots in pipes Find weakness in structures Treating disease Body imaging to find weak spots or problems Treat cancer by killing the effected cells

Try this! Uranium-238 Alpha Nickel-63 Beta Iodine-131 Radium-226 Isotope Type of Decay Result Uranium-238 Alpha Nickel-63 Beta Iodine-131 Radium-226