Advertisements
Advertisements
Question
Give reasons for the following.
- Aluminum foils are used to wrap food items.
- Immersion rods for heating liquids are made up of metallic substances.
- Sodium and potassium are stored in kerosene.
- Mercury is used in thermometers.
Solution
- Aluminium is malleable, soft and does not react with food items, so it is used to wrap food items.
- Metals are good conductor of heat and electricity, so immersion rods are made up of metallic substances.
- Sodium and potassium are very reactive, they react with air and water, so they are stored in kerosene.
- Mercury is used in thermometers and barometers because of its high density and uniform expansion at different temperature.
APPEARS IN
RELATED QUESTIONS
The atomic number of an element X is 12.
(a) What must an atom of X do to attain the nearest inert gas electron configuration?
(b) Which inert gas is nearest to X?
What is meant by 22 carat gold? Name the metals which are usually alloyed with gold to make it harder.
Write ‘true’ or ‘false’ for the following statement :
Silver is used to make electric cables.
State two important uses of following metal
Uses of aluminium
Why are alkali metals kept in kerosene oil?
Name the following:
The chemical compound responsible for the green deposit on the surface of articles of copper.
Can you store pickle in an aluminium utensil? Give reason.
Which of the following two combinations are correct?
| Metal | Gas Evolved | |
| (i) | Copper | Yes |
| (ii) | Iron | Yes |
| (iii) | Magnesium | No |
| (iv) | Zinc | Yes |
Metals have high melting points.
Why are metalloids called semimetals?
