CHAPTER 6 – CYU
6.1
1.a)
1.b)
2.a)
3.a)
3.b)
If you go anywhere in the world, the symbols will be the same for each element.
H – hydrogen (English), H – wasserstoff (German)
Cu
b) S
c) H2O
Hydrogen – 2, Oxygen – 2
molecule – the smallest independent unit of a pure substance. H2O
Diatomic molecule – when 2 atoms of the same element exist together as a result of
sharing electrons. O, N, F, Cl, Br, I, H
4.a)+b)
Antimony – Sb
Lead – Pb
Arsenic – As
Mercury – Hg
Bismuth – Bi
Silver – Ag
Carbon – C
Sulfur – S
Copper – Cu
Tin – Sn
Gold – Au
Zinc – Zn
Iron – Fe
5.a)+b)
Co – Cobalt
Pt – Platinum
Ni – Nickel
H – Hydrogen
Cl – Chlorine
Mn – Manganeese
6.a) 31
b) 21
O – Oxygen
Mo- Molybdenum
Te – Tellurium
W – Tungsten
U – Uranium
Zr – Zirconium
Ti – Titanium
F – Fluorine
Sr – Strontium
Be – Beryllium
Cr – Chromium
N – Nitrogen
c) 21/31 = 68%
6.2
1. Malleability, conductivity, ductility, luster.
2. Oxygen + Carbon Cycles
Respiration = C6H12O6 + O2
→
CO2 + H2O + energy
Photosynthesis = CO2 + H2O + energy
→
C6H12O6 + O2
Nitrogen Cycle
Nitrogen in air is absorbed by plants in roots. Bacteria returns it to atmosphere.
Water Cycle
Rain → run-off → evaporation → condensation → rain
3. Nitrogen – 78%, Oxygen – 21%, Argon – 1%, CO2 , Neon, Helium, Krypton, Xenon.
6.3
1. Ore – a body of rock
Mineral – a natural pure substance found in ore.
Concentration + decomposition
Physical + chemical
2. Smelting – process of melting ore to obtain metal
Iron, Silver
3. Al2O3 – Aluminum oxide
Al2O3 is mixed with Na3AlF6 because it dissolves Al2O3. Then adding a strong
electric current decomposes it. It then separates the Al to the bottom of the holding
tank.
4. Alumina - Al2O3
Hematite – Fe2O3
Magnatite – Fe3O4
6.4
1. Cu, Ag, Au
Chemical property – un-reactive with most acids
- not readily forms compounds with oxygen
Physical property – very malleable
- best conductors of electricity
2.a) solid at room temperature
2.b) group # 16
2.c) period # 4
3. Mendeleev arranged his in order of increasing atomic mass. The modern table which
was rearranged by Moseley is arranged in increasing atomic number from left to
right. It was similar in that they were arranged in families, but they were listed
horizontally instead of in vertical columns.
4. A family of elements refers to elements with the same chemical properties
Alkali metals – very reactive metals (group 1)
Halogens – very reactive non-metals (group 17)
Noble gases – non-reactive gases (group 18)