Answers and explanation:
To answer these questions you use a periodic table.
A is In because it has 49 protons and In is element number 49.
B is 27 because Co is element number 27.
C is 73 because Ta is element number 73.
D is 49 because the number of electrons in an atoms is always equal to the number of protons.
E is 56 because the atomic number of Ba is 56.
F is 54 because 56 - 54 = 2. The charge is equal to the number of protons minus the number of electrons.
G is 66. The number of neutrons is equal to the atomic mass minus the number of protons. 115 - 49 = 66.
H is 108 because 181 - 73 = 108.
I is 32. The atomic mass of an element is equal to the amount of protons plus the amount of neutrons. So 16 + 16 = 32.