In which unit, noise pollution is

Which one amongst the following is  not a Green House gas?

Which of the following is a physical change?

The element used in the manufacture  of safety matches is —

An electric iron has a heating element made of:

The absolute value of the charge on electron was determined by-

The acid used in lead storage cells is-

The most reactive among the halogens is-

Bronze is an alloy of-

The nucleus of an atom consists of-

The fuel that is used in modern  submarines is -