Halogen are the most reactive due to their electronic configuration
72.6g
The density formula is density equal mass divided by volume (d=m/v) to solve this you must get the mass by itself. You do this by multiply volume on both sides which then gets you density times volume equal mass. Then you can plug in the numbers which is 1.20g/mL x 60.5 mL the mL cancels out which leaves you with grams and thus you have 72.6g.
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
