11. What is the mass number
of an element if its atom
contains 10 protons, 10
electron, and 12 neutrons?
A 12
C20
D. 32

The mass numbr is 22

Explanation:

Mass number=number of protons+ number of neutronswhich is 10+12=22

> 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.