The mass number is the number of protons plus the number of neutrons. Since there are 16 neutrons, there are 14 protons. This also corresponds to the atomic number, so this atom's atomic number is 14 which is also Silicon
Answer:
The correct option is C
Explanation:
From the question we are told that
The reaction is

Generally
Here
is the change in enthalpy
is the change in the internal energy
is the difference between that number of moles of product and the number of moles of reactant
Looking at the reaction we can discover that the elements that was consumed and the element that was formed is
and
and this are both gases so the change would occur in the number of moles
So
The negative sign in the equation tell us that the enthalpy
would be less than the Internal energy 
Answer:
Chadwick-he discovered the neutron. He discovered this by demonstrating a neutral particle with a mass the same as a proton through a reaction between gramma Ray's and a wax sample.
Rutherford-he discovered the concept of radioactive half-life, the radioactive element radon, and named alpha and beta radiation.
j.j.Thompson discovered that atoms where made up of smaller components. This had major effects for the field of physics.
:)