C. 14
you would subtract the mass number from the protons or the atomic number because in order to find the mass number you would add the protons and neutrons :)
In the context of chemistry, yes. Energy input is always equal to the energy output.
The mass of the solid product of the reaction is determined by weighing.
Answer:
Explanation:
Sodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable isotope is ²³Na. The free metal does not occur in nature, and must be prepared from compounds.
