Is 2oh−+ca2+−> 2ca(oh)2 balanced

No.

Explanation:

No.  There is 1 atom of Ca on the left and 2 Ca's on the right  and 2 OH's on the left and 4 on the right.

The balanced equation is:

4OH-  +  2Ca2+ >  2Ca(OH)2.

Is not balanced

Explanation:

For an equation to be balanced there must be on each side of the equation the same amount of each atom.

2 OH−  +  Ca 2+   > 2 Ca(OH)2

On the left we have the following amounts of atoms:

Ca = 1

O = 2

H = 2

Total charges =  0

And on the right:

Ca = 2

O = 4

H = 4

Total charges =  0

We can see that on the right we have twice as many atoms as on the left, so we can delete a molecule of Ca(OH)2

                         2 OH−  +  Ca 2+   >  Ca(OH)2

Now the equation is balanced because there are the same number of atoms on both sides and also the charges are equal in both sides.

the answer to this question is 3.

the electron configuration that you gave me has 16 electrons ergo it has 16 protons ergo it is the element sulfur.