Which type of circuit allows current to flow in only one

Which of the following is the richest source of phosphorus?

Cinnabar is an ore of which metal?

Hydrogen was discovered by:

What are proteins chemically composed of?

Gunpowder consists of a mixture of:

The rate of evaporation increases with ______.

Which mineral is the ore Of aluminium ?

Radon, used in radiotherapy, belongs to which group on the periodic table?

Which chemical compound is used in the indelible ink for elections?

Identify the element that is NOT a metalloid.