Chapter 12 Elements: A Closer Look. Properties of Metals Worksheet Metals ¾ of all known elements...
Transcript of Chapter 12 Elements: A Closer Look. Properties of Metals Worksheet Metals ¾ of all known elements...
Chapter 12
Elements: A Closer Look
Properties of Metals
• Worksheet Metals• ¾ of all known elements• Solid at room temp (NOT Mercury)• Low IE = give up electrons• Metallic bonds– Delocalization• Malleable, ductile
Alkali Metals
• Alkali Metals Video• React with not only water, but many other
substances– Do not find in elemental state
• Sodium and potassium– Relatively abundant– nerve impulses• Your body would not function correctly w/out these• Ion imbalance effects
Alkaline earth metals
• Alkali and Alkaline Earth Metals Video• Denser, harder, higher melting & boiling• Less reactive– Still not found in elemental form
• Magnesium and calcium most abundant– Magnesium is the most important
• Alloys
– Calcium most commonly CaCO3
• Seashells, limestone
– Hard Water
Aluminum
• Earth’s crust• Commercial production• Aluminum Video
Transition Elements
• Reactivity• In nature• Hardness & melting/boiling points• Color• Magnetism• LAB: Colorful Transition Metals
Uses of Transition Metals
• Copper– Coins – nickel and penny– *Electrical conductor – Water transport
• Silver– Photographic film
• Alloys– Different properties (chemical and physical) than individual
metals• Increased strength, hardness• Lower electrical and thermal conductivity• Lower melting point
Properties of Alloys (Cont)
Impurities (in this case, C) occupy the spaces between atoms
This makes the alloy stronger because atoms cannot slide past each other
Lower electrical conductivities result because impurities block the path of e- in the electron sea
Lower melting points result due to imperfect crystalline structure
Fe
C
Metalloids
• Properties of both metals and nonmetals– Nonmetallic structure and chemical behavior– Luster– Conduct electricity• Not as well as metals = semiconductors
• Silicon– Metallic luster, but diamond structure– Most common metalloid– Quartz
Metalloids as Semiconductors
• Remember: Silicon is poor conductor– Certain impurities increase conductivity• As small as 1 : 1,000,000!!• Called doped crystals
– Impurities affect silicon in two ways• N-type • P-type
– Junctions: n-type next to p-type
Nonmetals - Carbon
• Distribution• Allotropes
Nonmetals – Nitrogen Family
• Natural occurrence• Reactivity• Nitrogen cycle
N2 + 8H+ + 8e- + 16 ATP 2NH3 + H2 + 16ADP + 16 Pi
2 NO3− + 10 e− + 12 H+ → N2 + 6 H2O
Nitrogen Family (cont)
• Phosphorus– White phosphorus• Reactivity• Physical properties• toxicity
– Red phosphorus• Physical properties
Nonmetals – Oxygen Family
• Oxygen– Abundance– Reactivity– Cellular respiration– O3 allotrope
• Sulfur– Abundance– Industrial
iron and steel (cars, appli-ances); 1%
other industrial (explsoives,
synthetic rub-ber); 6%
Petroleum (aviation, gaso-
line, lubricants); 2%
Pigments, fibers and film;
3%
Mixed fertilizers; 54%
Titanium and pigments (paints,
linoleum, paper); 5%
Chemicals (detergents, food additives, catalysts, an-
tifreeze); 17%
Nonmetals – Halogens and Noble Gases
• Diatomic• Reactivity– Halogens Video
Nonmetals - Noble Gases
• Helium• Neon• Argon• Krypton• Xenon• Radon