Q2. The table gives the composition of three particles. number of
number
of
number of
electrons
particle
neutrons
protons
A
15
15
16
B
15
18
16
A
с
15
15
17
(a) What is the evidence in the table for each of the following?
Particle A is an atom.
[1]
R. A.

Because electrons have negligible mass, to account for the mass of the isotope, there must be 16 neutrons, 16 neutrally charged, massive, fundamental particles present in the sulfur nucleus. and thus finally, if we have the 32s2− ion, there are 18 electrons, 16 protons, and 16 neutrons.