Answer:
Mercury has a density of 13.6g/mL
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.
Grass contains water and sheep need water.
Older trees can survive with the bark stripped from up to half the trunk diameter. If the bark is stripped all the way around the tree, it will die unless the damage can be repaired with bridge grafts.
