CBSE Class 10 Chemistry Metals And Non Metals Worksheet Set 16

This printable CBSE Class 10 Science worksheet for Chapter 3, Metals and Non-metals, has 15 fill in the blank questions, each with the answer and a short explanation. It revises the physical properties of metals, the reactivity series, alloys, ores and extraction, ionic compounds and corrosion, and prints cleanly on a few pages.

Fill in the Blanks

Question 1. The elements that can easily be cut with a knife are ________ and ________.
Answer:
Sodium and potassium.
In simple words: Sodium and potassium are soft metals.

Teacher's Note:
1. Lithium is also soft.
2. These metals are stored in kerosene.

Question 2. At room temperature, one metal that is present in the liquid state is ________.
Answer:
Mercury. (Gallium and caesium melt just above room temperature.)
In simple words: Mercury is the only metal that is liquid at room temperature.

Teacher's Note:
1. Bromine is the only liquid non-metal.
2. Mercury is used in thermometers.

Question 3. Cinnabar is an ore of ________.
Answer:
Mercury (HgS).
In simple words: Cinnabar is mercury sulphide.

Teacher's Note:
1. Cinnabar is roasted to give mercury.
2. Heating HgS gives HgO, which then yields mercury.

Question 4. When copper is kept in open air it slowly loses its shining brown surface and acquires a green coating. This is due to the formation of ________.
Answer:
Basic copper carbonate, CuCO₃.Cu(OH)₂.
In simple words: The green coating is basic copper carbonate.

Teacher's Note:
1. Copper reacts with moist CO₂ and oxygen of air.
2. Lemon or tamarind juice removes the coating.

Question 5. During electrolytic refining of zinc, zinc is deposited on the ________.
Answer:
Cathode. Pure metal collects at the cathode.
In simple words: Pure metal is always deposited at the cathode.

Teacher's Note:
1. The impure metal is the anode.
2. The cathode is made of a thin strip of pure metal.

Question 6. Metals combine with oxygen to form ________ oxides.
Answer:
Basic oxides.
In simple words: Metal oxides are basic in nature.

Teacher's Note:
1. Some, like Al₂O₃ and ZnO, are amphoteric.
2. Non-metal oxides are acidic or neutral.

Question 7. Metals above hydrogen in the activity series can displace ________ from dilute acids.
Answer:
Hydrogen.
In simple words: Reactive metals push hydrogen out of acids.

Teacher's Note:
1. Copper, silver and gold are below hydrogen.
2. Hydrogen gas burns with a pop sound.

Question 8. The slow eating away of the surface of metals like iron on exposure to moist air is known as ________.
Answer:
Corrosion. For iron it is called rusting.
In simple words: Surface damage of metals by air and moisture is corrosion.

Teacher's Note:
1. Corrosion of silver gives a black coating.
2. Corrosion of copper gives a green coating.

Question 9. The best conductors of electricity are copper and ________.
Answer:
Silver. Silver is the best conductor, followed by copper.
In simple words: Silver conducts best, copper next.

Teacher's Note:
1. Lead and mercury are poor conductors.
2. Copper is used for wires because it is cheaper than silver.

Question 10. Manganese and ________ react with very dilute nitric acid to evolve hydrogen gas.
Answer:
Magnesium.
In simple words: Only Mg and Mn give hydrogen with very dilute HNO₃.

Teacher's Note:
1. Nitric acid is a strong oxidising agent.
2. With other metals, nitrogen oxides form instead.

Question 11. An alloy of any metal with mercury is called ________. The electrical conductivity of an alloy is ________ than that of pure metals.
Answer:
Amalgam; less.
In simple words: Amalgam contains mercury; alloys conduct less than pure metals.

Teacher's Note:
1. Brass conducts less than copper.
2. Alloys also usually have lower melting points.

Question 12. Stainless steel contains ________, ________ and ________.
Answer:
Iron, chromium and nickel (with a little carbon).
In simple words: Stainless steel is iron mixed with chromium and nickel.

Teacher's Note:
1. It does not rust easily.
2. It is used for utensils and surgical tools.

Question 13. The method of removing volatile matter from carbonate ores is known as ________.
Answer:
Calcination.
In simple words: Calcination is for carbonate ores.

Teacher's Note:
1. Roasting is for sulphide ores.
2. Both processes give the metal oxide.

Question 14. The main ore of copper is ________.
Answer:
Copper pyrite (chalcopyrite); copper glance (Cu₂S) is another ore.
In simple words: Copper pyrite is the chief ore of copper.

Teacher's Note:
1. Copper glance is Cu₂S.
2. Cuprite is Cu₂O.

Question 15. In electrolytic refining, the impure metal is used as the ________.
Answer:
Anode.
In simple words: The impure metal dissolves from the anode.

Teacher's Note:
1. Anode is the positive electrode.
2. Pure metal is deposited at the cathode.