Which is the purest commercial form of iron ?

Which of the following phenomenon is considered responsible for Global Warming?

A. Greenhouse effect

B. Fire in coal mines

C. Dry farming

D. Monsoon

E. Trade winds

The nucleus of an atom consists of

A. electrons and neutrons

B. electrons and protons

C. protons and neutrons

D. All of the above

The number of moles of solute present in 1 kg of a solvent is called its

A. molality

B. molarity

C. normality

D. formality

The most electronegative element among the following is

A. sodium

B. bromine

C. fluorine

D. oxygen