I thinks it's true but I'm not sure
You did not include the list but F is fluorine. The first halogen.
So, you can expect that the other members of the same group (halogens, column 17 of the periodic table) exhibit similar chemical behavior (reactivity).
So, I am sure your list contains one or more of theses elements: Cl (chlorine), Br (bromine), and I (iodine).
All of them you can expect to also be reactive non metal.
Was there supposed to be a picture?
<span>At a depth of 34 feet the diver experiences 2 atmospheres of pressure.
At a depth of 68 feet the diver is experiencing 3 atmospheres.
At a depth of 102 feet the diver is experiencing 4 atmospheres of pressure.
At one atmosphere of pressure the body is mildy compressed. As the diver descends the divers body will undergo increased compression instead of being squashed.</span>
