The term amphoteric describes a substance that can act as both an acid and a base.
2.2 x 10^-2
0.055 / 250 = 0.00022 - This would be 2.2 x 10^-4, but the question is asking for percent, not proportion, so multiply by 100% to get the percentage.
0.00022 * 100% = 0.022% = 2.2 * 10^-2
The atomic number is the number of protons in the nucleus of an atom. The number of protons define the identity of an element (i.e., an element with 6 protons is a carbon atom, no matter how many neutrons may be present).
Eukarya cause all cells with nuclei are considered eukaryotic
