Answer: 0.075
Explanation:
(concentration in molarity)(volume in liter) = answer
0.15 mol/L *0.500L = 0.075 mol
Planet, solar system, galaxy, universe
For any given element the mass number can be found by adding the protons and the neutrons.
In this case its 10 protons plus 11 neutrons which gives us 21 as the mass number.
