Consider the following statements

1. Ore is heated generally in the absence of air then process is called calcination.

2. Ore is heated generally in the presence of air, then process is called roasting.

3. Reduction of oxide with carbon at high temperature is called smelting.

Which of the above are true?

Consider the following statements

1. Gold is the most ductile metal.

2. The best conductors of heat are silver and copper.

3. Alkali metals (lithium, sodium, potassium) are so soft that they can be cut with a knife.

Which of the statements given above are correct?

Consider the following statements:

1. Galvanisation is the method of protecting steel and iron from rusting by coating them with a thin layer of zinc.
2. Pure iron is very soft but if it is mixed with a small amount of carbon, it becomes hard and strong.
3. When iron is mixed with nickel and chromium, we get stainless steel which is hard and does not rust.

Which of the statements given above are correct?

Consider the following statements

1. Silver articles become black after sometime when exposed to air because they reacts with sulphur in the air to form a coating of silver sulphide.

2. Copper reacts with moist carbon dioxide in the air and loses its shiny brown surface and gains a green coat of copper carbonate.

3. Iron when exposed to moist air for a long time acquires a coating of a brown flaky substance called rust.

Which of the statements given above are correct?