Metals and Non-metals
Subject: General Science
Sample Practice Questions
Question 1: Ionic compounds are formed by:
- Sharing of electrons
- Transfer of electrons from metal to non-metal
- Transfer of electrons from non-metal to metal
- Sharing of protons
Explanation: Ionic compounds (electrovalent compounds) are formed by the transfer of electrons from a metal atom (which loses electrons) to a non-metal atom (which gains electrons).
Question 2: Which of the following is a mineral that contains a high percentage of a metal and can be profitably extracted?
- Mineral
- Gangue
- Ore
- Alloy
Explanation: The text defines: 'At some places, minerals contain a very high percentage of a particular metal and the metal can be profitably extracted from it. These minerals are called ores.'
Question 3: Which of the following is a non-metal that is lustrous?
- Sulphur
- Carbon (diamond)
- Phosphorus
- Oxygen
Explanation: Iodine is a non-metal that is lustrous. Also, diamond, an allotrope of carbon, is lustrous. The text mentions: 'Iodine is a non-metal but it is lustrous.'
Question 4: What is the green coating on copper vessels due to?
- Copper oxide
- Copper carbonate
- Copper sulphide
- Copper chloride
Explanation: Copper reacts with moist carbon dioxide in the air and slowly loses its shiny brown surface and gains a green coat. This green substance is basic copper carbonate.
Question 5: The iron pillar near Qutub Minar in Delhi is known for:
- Being the tallest pillar
- Its resistance to rusting
- Being made of pure gold
- Its weight of 600 tonnes
Explanation: The iron pillar near the Qutub Minar in Delhi, built more than 1600 years ago, is known for its remarkable resistance to rusting. The iron workers of India had developed a process that prevented iron from rusting.
Question 6: Which of the following metals can displace hydrogen from dilute acids?
- Copper (Cu)
- Silver (Ag)
- Gold (Au)
- Zinc (Zn)
Explanation: Metals above hydrogen in the activity series can displace hydrogen from dilute acids. Zinc (Zn), iron (Fe), magnesium (Mg), etc., can displace hydrogen. Copper, silver, and gold are below hydrogen and cannot displace it.
Question 7: Which of the following is an alloy of copper and zinc?
- Bronze
- Brass
- Solder
- Amalgam
Explanation: Brass is an alloy of copper and zinc. Bronze is an alloy of copper and tin. Solder is an alloy of lead and tin.
Question 8: What is the process of heating carbonate ores in limited air called?
- Roasting
- Calcination
- Smelting
- Refining
Explanation: Calcination is the process of heating carbonate ores strongly in limited air to convert them into metal oxides. For example: ZnCO3 → ZnO + CO2.
Question 9: What is the nature of the solution formed when magnesium oxide dissolves in water?
- Acidic
- Basic
- Neutral
- Amphoteric
Explanation: Magnesium oxide (MgO) is a basic oxide. When dissolved in water, it forms magnesium hydroxide, which is a base: MgO + H2O → Mg(OH)2.
Question 10: What is the process of converting sulphide ores into oxides by heating in excess air called?
- Calcination
- Roasting
- Smelting
- Refining
Explanation: Roasting is the process of heating sulphide ores strongly in the presence of excess air to convert them into metal oxides. For example: 2ZnS + 3O2 → 2ZnO + 2SO2.