In each of the symbols above, what does the bottom number tell us?

mass

Explanation:

The total mass is located at the bottom, right underneath the symbol of the element. The mass is the sum of both the protons and neutrons for both are equivalent in mass whereas the electrons have almost no mass at all.

> b takes place in the gas phase in an isothermal tubular reactor. the feed is one mole of a per one mole of c, an inert. the entering temperature and pressure are 427°c and 10 atm, respectively. the gas constant r = 0.08206 atm · l/mol · k.