A teacher took students of grade 8 to chemistry lab to show experiments. She took a test tube containing acid and added granules of a metal A in it. After some time bubbles appeared in the test tube. She took another test tube containing same acid and added another metal B to it. Bubbles did not appear.•What could be A and B?•How can you test the gas produced?

A teacher took students of grade 8 to chemistry lab to show experiment

1.	A teacher took students of grade 8 to chemistry lab to show experiments. She took a test tube containing acid and added granules of a metal A in it. After some time bubbles appeared in the test tube. She took another test tube containing same acid and added another metal B to it. Bubbles did not appear.•What could be A and B?•How can you test the gas produced?
Answer» Metal A is ZINC and Metal B is Gold.The acid might be either Hydrochloric or Sulphuric AcidYou can test the gas produced by BRINGING a candle close to the bubbles. If they BURNS with pop sound hydrogen gas is liberated