Why does silver get tarnished on exposure to air?

Which property of metals makes them suitable for use in jewellery?

Name the colourless gas that evolves when potassium reacts with water. How will you test this gas?

What is malleability? Which of them shows the malleability-metal or non-metal?

A piece of magnesium is put in a test tube containing hydrochloric acid. Explain the chemical reaction.

Which metal is used to make foils for packaging of food? Explain

What do you understand by a displacement reaction? Give one example.

Non-metal oxides are acidic oxides. Explain this with an example.

The colour of silver nitrate solution changes when a copper rod is dipped in it. Explain with the help of the chemical reaction involved.