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.
Igneous rock forms from heat and pressure
At room temperature, water is liquid in form. For helium, it is gas because it is the second lightest element in nature. So, you would expect the density of Helium to be much less than 1 g/cm³. Because gas is very light and occupies a lot of space, the density would result to a very small number.