Chemical

The chemical name of chalk is

A. Sodium nitrate B. Zinc sulfate C. Sulphuric acid D. Calcium carbonate Explanation: Calcium carbonate (also known as chalk), mined as…

4 years ago

Combustion can not take place without __________?

A. Hydrogen B. Air C. Oxygen D. Argon Explanation: Combustion can not take place without air. Air contains about 21% by…

4 years ago