Which metal that is usually extracted from sea water?
Why Radiocarbon is produced in the atmosphere?
It is easier to roll a stone up a sloping road than to lift it vertical upwards, what is the reason behind this?
The absorption of ink by blotting paper involves which phenomenon?
What is the most important ore of aluminium?
The human body is made up of several chemical elements, which element present in the highest proportion (65%) in the body?
What is the main active constituent of tea and coffee?