Q.:- On the basis of Rutherford’s model of an atom, which sub-atomic particle is present in the nucleus of an atom?   Answer:- Proton, positively charged subatomic particle is present…

Q.:- On the basis of Thomson’s model of an atom, explain how the atom is neutral as a whole.   Answer:- According to Thomson’s model of an atom : (a)…

Q.:- If an atom contains one electron and one proton. Will it carry any charge or not?   Answer:- No, the atom will not carry any charge because electron has…

Q.:- What are canal rays?   Answer:- The beam of rays which travel in a direction away from anode towards cathode when a gas taken in a discharge tube is…

Q.11:- Calculate the number of aluminium ions present in 0.051 g of aluminium oxide. (Hint: The mass of an ion is the same as that of an atom of the…

Q.10:- Calculate the number of molecules of sulphur (S8) present in 16 g of solid sulphur?   Answer:-

Q.9:- What is the mass of (a) 0.2 mole of oxygen atoms? (b) 0.5 mole of water molecules?   Answer:- (a) Mass of 1 mole of oxygen atom = 16 u…

Q.8:- Convert into mole. (a) 12 g of oxygen gas (b) 20 g of water (c) 22 g of carbon dioxide   Answer:- (a) Molar mass of O2 = 2 x…

Q.7:- What is the mass of (a) 1 mole of nitrogen atoms? (b) 4 moles of aluminium atoms (atomic mass of aluminium = 27)? (c) 10 moles of sodium sulphite…

Q.6:- Calculate the molar mass of the following substances. (a) Ethyne, C2H2 (b) Sulphur molecule, S8 (c) Phosphorus molecule, P4   (atomic mass of phosphorus = 31) (d) Hydrochloric acid, HCl…