Is this fill in the blank?
Answer:
1,2,5
Explanation:
Hydrogen can't really be classified into any group in the periodic table because it doesn't have properties that match that of any group exactly. However it exhibits a property of group 1A (formation of a univalent positive ion) and that of group 7A (formation if a univalent negative ion). It contains only one electron, hence this outermost electron is not shielded at all from the nucleus.
HOMER - <span>hypothesize, operationalize, measure, evaluate, and replicate/revise/report."</span>
Because they are different elements have different number of protons and neutrons........ I guessed do not trust me...