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 Beta

Iodine-131 Beta

Radium-226 Alpha