Answer:
D
Explanation:
Just look at the groups and their tendencies. Or look at their electron configurations. You will notice that calcium has 2 valence electrons and bromine has 7 valence electrons.
Halogens have the most valence electrons possible without completing a shell (8 would be needed for that)
Solid particles are all compacted together, liquid particles are not as close as solid particles but still move together, and gas particles do not stay together
Mass % of nitrogen = mass of nitrogen*100 / total mass
= 14*100 / (1+ 14 + 32)
= 14*100 / 47
= 29.7 %
