Metals and Non-Metals

One Marks Questions

Answer: Metals in their pure state have a shining surface.

Answer: Metals can be beaten into thin sheets.

Answer: Metals drawn into thin wires.

Answer: Silver and copper

Answer: Polyvinyl Chloride

Answer: Bromine

Answer: Carbon, Sulphur, Oxygen, Iodine etc.

Answer: Mercury

Answer: Iodine

Answer: Sodium

Answer: Diamond

Answer: Sodium

Sodium is a highly reactive metal, kept open it will react with oxygen in the air.

Answer: 3 Fe(s) + 4 H2O → Fe3O4 (s)+ 4H2

Answer: The elements or compounds which occur naturally in the earth's crust.

Answer: Silver reacts with Sulphur in the air to form silver sulphide

Answer: Carbon (about 0.05 %)

Answer: amalgam

Two Marks Questions

Answer:
Some metal oxide react with both acids and bases to produce salt and water are known as amphoteric oxides.

example:
Al2O3 + 6HCl → 2AlCl3 + 3H2O

Answer:
a) Because metals are sonorous
b) Copper is a good conductor of electricity

Answer:
2Na + 2 H2O → 2NaOH + H2 (g)

X is sodium, Y is sodium hydroxide, Z is hydrogen gas.

Answer:
Corrosion is a process in which metals react with substances present in the environment to form surface compounds.
prevention methods:
galvanization, electroplating, the concentration of ore, electrolytic refining

Answer:
Al2O3 + 6 HCl → 2AlCl3 + 3H2O

Al2O3 + 2 NaOH → 2NaAlO2 + H2O

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Three and Four Marks Questions

Answer:
a) Mineral: the naturally occurring chemical substances which contain metals with other elements or impurities is called mineral.
b) Ore: the minerals from which metals can be extracted economically on large scale are called ores.
c) Gangue: the impurities present in ore or minerals are called gangue.

Answer:
a) reaction of iron(III) oxide with aluminium used to join cracks in machines.
uses:
to join railway tracks
to join cracked machine parts.

b) the metals( K, Na, Ca, Mg etc) Can be isolated by carrying out the process of electrolysis (electric reduction) from their molten salts.

Answer:
Roasting is a process in sulphide Ore is heated in the presence of oxygen to convert into oxide.

2ZnS +3 O2 → 2 ZnO + 2 SO2

is a process carbonate Ore is heated in the absence of air to form oxide.

ZnCO3 (s) → ZnO (s) + CO2 (g)

by reduction process, zinc can be extracted from its ore.

reduction: ZnO + C → Zn + CO2

b) Aluminium, Magnesium

Answer:
Alloys are a homogeneous mixture of two or more metals. One of them can be a non-metal also. They are made of metal which is in large amount first and then adding to other metal. Brass contains Copper and Zinc. it is used for making decorative articles. bronze contains Copper and Tin. It is used for making statues and medals. Solder contains lead and Tin. It is used for soldering purposes.