how many protons and nuetrons are contained in the nucleus of each of the following atoms? assuming each atom is uncharged, how many electrons are present?

Question

a. 235/92U
b. 13/6C
c. 57/26Fe
d. 208/82Pb
e. 86/37Rb
f. 41/20Ca

Answer 1

I'll do a couple.
U92 means atomic number is 92. So yo have 92 protons and 92 electrons.
235 is the mass number. That is the number of protons + number of neutrons; therefore, 235 = ?? number of neutrons + 92 protons. Thus 235-92 = number of neutrons.

C6-12.
6 protons. 6 electrons. 12-6 = 6 neutrons.

Answer 2

56 protons and 80 neutron