1. Common knowledge : Go to the right of periodic table, the atomic radius is decreasing
2. Flurine has 9 protons and lithium has 3 protons. you know that the electron is attracted with the centre of the atom, that's why more proton, more 'energy' that attract to the centre and that's why it make the shape of the atom is smaller
In mineralogy and crystallography, a crystal structure<span>is a unique arrangement of atoms in a </span>crystal. Acrystal structure<span> is composed of a unit cell, a set of atoms arranged in a particular way; which is periodically repeated in three dimensions on a lattice.
Crystals create a harder more fitting structure so they tend to be a lot stronger than other compounds or elements</span>
Molecules move more slowly in solids because there they are all very compact
