Step by step solution: The position of hydrogen is controversial in the periodic table because hydrogen is the only element without neutrons. Hydrogen is a nonmetal and is placed above the group in the periodic table because it has ns1 electron configuration like the alkali metals.
Aluminum is an element. If there's nothing else in the foil
besides aluminum, then the foil is entirely an element.
An electron in the 3s orbital. The order of electron orbital energy levels starting from lowest to highest is as follows: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p.
