good morning minions please answer the question on the board
TRANSCRIPT
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