Lithium (Li)
The element with 4 electron shells is potassium (K).
The atomic number of the element with the symbol Be (Beryllium) is 4.
berylium has 4 protons. It has 4 electrons too.
Element Phosphorus has an oxidation state of -4. No element has oxidation state of +4. Phosphorus is denoted by "P".
The element in period 4 of the Periodic Table with the highest electronegativity is krypton (2.96). The period 4 element with the lowest electronegativity is potassium (0.82).
Be
The element in period 4 group 2A is calcium (Ca).
element K, or potassium
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.
Lead is a brittle metallic element with 4 letters.
Iron (Fe) is the element that has 4 unpaired electrons in its electron configuration.