Same proton number

Same electronic configuration

Same electron number

Same size

$22.4\,\,{\rm{litre}}$

$11.2\,\,{\rm{litre}}$

$1.12\,\,{\rm{litre}}$

$2..24\,\,{\rm{litre}}$

$18 imes {10^{23}}$ electrons

$6.023 imes {10^{23}}$ electrons

$3.01 imes {10^{23}}$ electrons

$9 imes {10^{23}}$ electrons

$\,{\rm{1}}{{\rm{0}}^{{\rm{ - 3}}}}\,{\rm{mol}}\,\,{\rm{of}}\,{\rm{water}}$

${\rm{18}}\,{\rm{mL}}\,{\rm{of}}\,{\rm{water}}$

$\,{\rm{0}}{\rm{.00224}}\,{\rm{L}}\,\,{\rm{of}}\,{\rm{water}}\,{\rm{vapours}}\,\,{\rm{at 1 atm }}\,{\rm{and }}\,{\rm{273}}\,\,{\rm{K}}$

${\rm{0}}{\rm{.18}}\,\,{\rm{g}}\,\,{\rm{of}}\,\,{\rm{water}}$

$26.9 imes {10^{18}}$ molecules

$2.69 imes {10^{19}}$ molecules

$2.69 imes {10^{18}}$ molecules

$26.9 imes {10^{19}}$ molecules

$6.022 imes 10^{23}$

$3.011 imes 10^{23}$

$1.204 imes 10^{24}$

$1.806 imes 10^{24}$

$6.02 imes {10^{23}}{\rm{atoms}}\;{\rm{of}}\;{\rm{C}}$

$6.02 imes {10^{23}}{\rm{atoms}}\;{\rm{of}}\;{\rm{O}}$

$3.01 imes {10^{23}}molecules\;of\;C{O_2}$

None of the above

18 moles of water

18 molecules of water

18 grams of water

18 g of $O_2$

Twice that in 60 g carbon

$6.023 imes {10^{22}}$

Half in 8 gr of He

$558.5 imes 6.023 imes {10^{23}}$

$6.02 imes {10^{23}}$ atoms of H

4 g.atom of Hydrogen

$1.81 imes {10^{23}}$ molecules of $C{H_4}$

3.0 g of carbon

$6.02 imes {10^{23}}{\rm{atoms}}\;{\rm{of}}\;{\rm{C}}$

$6.02 imes {10^{23}}{\rm{atoms}}\;{\rm{of}}\;{\rm{O}}$

$3.01 imes {10^{23}}molecules\;of\;C{O_2}$

None of the above