"An atom or ion has 43 neutrons , 36 protons, and 36 electrons. Identify the element symbol, and determine the mass number and charge for this atom or ion."

1. Mass number = 79

2. No charge

Explanation:

From the question given, we obtained the following data:

Neutron = 43

Proton = 36

Electron = 36

Mass number = proton + Neutron

Mass number = 43 + 36

Mass number = 79

Atomic number = proton number = 36

Therefore the element is Krypton (Kr).

The element has no charge since the proton number and electron are the same. its outer shell is completely filled being a member of the noble gas family(i.e group 0). From the calculations made above this element is simply an isotope of krypton because krypton has a mass number of 84 normally. Since the mass number(79) obtained above is different from this(84), it therefore means they have a different neutron number which is the basis for isotopy.

the potential energy of the reactants is 200j.

from the energy diagram, the energy of the product formed is 350j; this means that, this reaction is an endothermic reaction, because it absorbs energy from its environment.