GOOD MORNING MINIONSPlease answer the question on the board.

NONMETALS• Properties

• 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

• 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!Isotope Type of Decay Result

Uranium-238

Alpha

Nickel-63 BetaIodine-131 Beta

Radium-226 Alpha