Which will have more density: one gram of cotton or one gram of iron?

Which has more number of atoms, 100 gram of sodium or 100 gram of iron ( given atomic mass of Na= 23 u, Fe=56u)?

Write the name of one ore of iron.

Calculate mass of one atom of nitrogen in gram .

Which photon is more energetic: A red one or violet one?

how many kilocalories of energy are produced by the oxidation of one gram of carbohydrates?

Calculate number of gram atoms in 669.6 g of iron?