Advertisements
Advertisements
प्रश्न
Give a reason why iron objects rust easily but the iron pillar at Qutab Minar has not rusted over the years.
Advertisements
उत्तर
The iron pillar at Qutab Minar has not rusted for 1600 years because of the following reasons:
- The high purity and great mass of iron may have created a temperature stabilizer thus reducing the condensation of moisture on it.
- The protective scale or passive iron coating formation on the surface, better forge welding and absence of impurities in iron – also may have dissuaded corrosion.
APPEARS IN
संबंधित प्रश्न
Brass is an alloy of copper and ______.
Fill in the blank
A metal that gives dazzling effect to crackers when they explode is ______
A metal with melting point less than 50°C is
State two important uses of following metal:
Uses of silver
Why are alkali metals kept in kerosene oil?
Write name.
Molecular formula of the common ore of aluminium.
With reference to the following metals state their use in daily life metal:
Lead
State why telegraph poles are painted with aluminium paint.
State a specific reason for using copper in electrical cables
Compare the properties of metals and nonmetals. Give three examples for each.
Higher Order Thinking Skills.
Aakash noticed that the metal latch on gate was difficult to open during hot sunny days. However, it was not difficult to open the same latch at night. Aakash observed that the latch and the gate are exposed to the sun during day time.
- Formulate a hypothesis based on the information provided.
- Briefly state how you would test the hypothesis.
Why are bells made of metals?
Which of the following two combinations are correct?
| Metal | Gas Evolved | |
| (i) | Copper | Yes |
| (ii) | Iron | Yes |
| (iii) | Magnesium | No |
| (iv) | Zinc | Yes |
Which one of the following metals do not react with cold as well as hot water?
Metals are usually solids or gases at room temperature.
Name two soft metals which can be cut with a knife.
Metals and non–metals are used for making ______, ______ and ______.
Compare the conductivity of metals and non–metals.
X [2, 8, 7] and Y [2, 8, 2] are two elements. Using this information, complete the following:
______ is the reducing agent.
