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.
It will also be halved... but the relationship is with Kelvin not c. So 273 +273 = 546 K. half of that is 273 K, then subtract 273... you get 0 degrees c
The number of sigma and pi bonds are,
Sigma Bonds =
16 Pi Bonds =
3Explanation: Every first bond formed between two atoms is sigma. Pi bond is formed when already a sigma bond is there. While in case of Alkyne (triple Bond) there is one sigma and one pi bond already present, so the third bond is formed by second side-to-side overlap of orbitals, hence, a second pi bond is formed.
Below all black bonds are sigma bonds, while in alkene there is one pi bond and in alkyne there are two pi bonds.
Yes. Parts of a cell work together just like stations in a factory.
