An element has 8 protons and 8 neutrons in its nucleus and 8 electrons revolving around the nucleus. what is the atomic number and atomic mass of this element?

The atomic number of the element is 8 (this is because the atomic number is determined by the muber of protons or electrons). The atomic mass of the element is 16 (this is because the atomic mass is equal to number of protons+number of neutrons

Atomic number = number of protons 
Atomic mass = number of protons + neutrons

Atomic mass = 8 + 8 
Atomic mass = 16

Atomic number = 8

Answerδh > 0explanationc₆h₆  (s)  → c₆h₆ (l)if you are changing it from a solid to a liquid, you are pretty much melting the solid. this requires heat energy. therefore, the reaction is endothermic (takes in energy); the system enthalpy increases as the reaction proceeds: δh > 0.