The element that is most reactive to gas is Hydrogen
This question is incomplete. Luckily, I found the same problem which is shown in the attached picture. To answer the question, we must know how the size and charge affect the lattice energy. The answer is: lattice energy increases with the increasing charge of the ions, and decreasing radius of the atoms.
<em>Therefore, the ranking would be: A < B < C</em>.
He did experiments with combustion and gas's
Answer: 1. rock stone gase from developing the other difference
Element X is sodium.
If there is one more shell of electrons, then this means it is one period below.
Since there is one less valence electron, it is one group to the left.