If you mean the first 2 elements in the periodic table, they are the Hydrogen H and the Helium He. The periodic table is always read horizontally.
Just for more information, Hydrogen is used in rocket fuels and hydrogen bombs, and the Helium is commonly used for filling balloons (And yes that's the element that gives you a funny voice if you inhale it :p )
the number of neutrons in above isotope = A - Z = 27 - 13 = 14. Note: The molar mass of aluminium, which is average of atomic masses of all isotopes = 26.981538 g/mol, since 13Al27 is the major isotope.
