Br (Bromine) is a period 4 element in the same group as F.
There is no element with 28 protons in group 4. I think you are getting confused with group 4 and PERIOD 4. In period 4, the element with 28 protons is Nickel.
Germanium, belongs to period 4, group IVA (or group 14)
There is no such element on the Periodic Table
element K, or potassium
Chromium is the element in period 4 and group 6.
Germanium belongs to group IVA or group 14 and period 4
Krypton.
It is iron.
Calcium
The element is krypton (Kr)
Chromium