It will received an H+. I’m not sure if that answers your question correctly
Cu,it would most likely be a shiny solid at room temperature and have high density. •ω•
I'm pretty sure it would make it unstable, hydrogen only has one proton thus having the ability to stabilize one electron, adding another electron would most likely make the atom reactive to any positively charged atom to loose this extra electron.
One mole of any element is Avogadro's number, which is 6.02 * 10^23 atoms.
One mole of Calcium is equal to its atomic weight in grams, 1 mole Ca = 40.08 x 1000 mg = 6.02 * 10^23 atoms.
We have 8.6mg of Ca which means 8.6mg / 40,080mg = .00021457 of a mole of calcium.
Now multiply that by Avogadro's number which gives number of atoms = 0.00021457 * 6.02 * 10^23 atoms. So the answer is 1.292 * 10^20 atoms of Ca.