State the postulate of Dalton's atomic theory which led to the law of conservation of mass. Calculate the molecular mass of water.

Which of the following will have maximum mass?

Which of the following statements is not true about an atom?

Give the formulae of the compounds formed from the following sets of elements:
$(a)$ Calcium and fluorine
$(b)$ Hydrogen and sulphur
$(c)$ Nitrogen and hydrogen
$(d)$ Carbon and chlorine
$(e)$ Sodium and oxygen
$(f)$ Carbon and oxygen

In photosynthesis,$6$ molecules of carbon dioxide combine with an equal number of water molecules through a complex series of reactions to give a molecule of glucose having a molecular formula $C_6H_{12}O_6$. How many grams of water would be required to produce $18\, g$ of glucose? Compute the volume of water (in $cm^3$) so consumed assuming the density of water to be $1\, g\, cm^{-3}$.

$(a)$ Define the following:
$(i)$ Mole
$(ii)$ Gram atomic mass
$(iii)$ Gram molecular mass
$(b)$ Calculate the mass of the following:
$(i)$ $2$ moles of carbon dioxide
$(ii)$ $6.022 \times 10^{23}$ molecules of carbon dioxide.