7th Grade Ch 3 Sec 4 Nonmetals & Metalloids
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Transcript of 7th Grade Ch 3 Sec 4 Nonmetals & Metalloids
Ch. 3 Ch. 3 Sec. 4 Sec. 4
Nonmetals & Nonmetals & MetalloidsMetalloids
NonmetalNonmetal•Element that lacks most properties of metals–dull- not shiny–brittle- not malleable–poor conductors
NonmetalsNonmetals•Located at right of zigzag line on periodic table
•10/16 = gases•Most form compounds, except Group 18
The table salt on a pretzel is mined from deposits
found on Earth. The same
compound can also be formed from a reaction
between the metal sodium and the
nonmetal chlorine.
Boron FamilyBoron Family
•Group 13
Carbon FamilyCarbon Family• Group 14• C (nonmetal) Pb• 4 valence electrons
Carbon FamilyCarbon Family•Contains elements
important to life & computers
•Carbon = basis for an entire branch of chemistry
•silicon & germanium- important semiconductors
Nitrogen FamilyNitrogen Family• Group 15• N Bi• 2 nonmetals- N & P• 5 valence electrons
Nitrogen Nitrogen FamilyFamily
• Group 15• Nitrogen makes up
over ¾ of the atmosphere.
• Nitrogen and phosphorus are both important in living things.
• Most of the world’s nitrogen is not available to living things.
• The red stuff on the tip of matches is phosphorus.
Diatomic Diatomic moleculesmolecules
•Compounds of 2 identical
atoms
Oxygen FamilyOxygen Family• Group 16• O Po• 3 nonmetals- O, S, Se• 6 valence electrons
Halogen FamilyHalogen Family• Group 17• F At• 7 valence electrons• very reactive• typically gains or shares 1 electron
HalogensHalogens• Group 17• Very reactive,
volatile, diatomic, nonmetals
• Always found combined with other element in nature
• Used as disinfectants & to strengthen teeth
Noble GasesNoble Gases• group 18• He Rn• 8 valence electrons• very stable & unreactive• do not form compounds b/c do not gain,
lose, or share valence electrons
The Noble GasesThe Noble Gases• Group 18• VERY unreactive,
monatomic gases• Used in lighted
“neon” signs• Used in blimps to
fix the Hindenberg problem.
• Have a full valence shell.
The The Noble Noble GasesGases
HydrogenHydrogen• alone in upper corner• not grouped in a family• very diff. properties • has 1 proton & 1 electron• some have neutrons
MetalloidsMetalloids•on border between metals & nonmetals
•8 metalloids•characteristics of both metals & nonmetals
MetalloidsMetalloids•most useful property= varying ability to conduct electricity–used to make semiconductors= can conduct electricity under certain conditions
Periodic Table of ElementsPeriodic Table of Elements
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
Alkali metals
Very reactive
Li
Fr
Name each family and give a description of each, include examples from each group.
Name______________________ Date________________
Bo