Answer:
-2
Explanation:
Calcium is the element of second group and forth period. The electronic configuration of Calcium is - 2, 8, 8, 2 or 
There are 2 valence electrons of Calcium.
Thus, calcium loses two electrons to sulfate ion and sulfate ion accepts these electrons to form ionic bond.
Calcium sulfate, 
is formed when 2 valence electrons of calcium are loosed and they are gained by sulfate ion.
Thus, the charge on the sulfate ion is -2.
Answer:
yo try and search it on Google
The answer should be B - Nitrogen Dioxide.
Yes. If this is the balanced equation:
AlCl3 + 3Na —— 3NaCl + Al
then Al was reduced from a 3+ oxidation (to neutralize the 3- from the chlorine) to a 0 oxidation (elemental ground state).
I'm pretty sure since one chemical can only bind with one other type, um, I think that one side of the DNA helicase helps make the other side?
