How many valence electrons would atoms of the element oxygen have?

the answer is 8 electrons

6 valence electrons

Explanation:

Electronic Structure of oxygen : 2,8,6

The last outer shell holds 6 valence electrons

You can find this out also by the group number

Hope this helps!

b is the correct

2fe + 3h2so4 -> fe2(so4)3 + 3h2

it is necessary to balance equations in order to get the proper amount of reactants as well as products in order not to make a miscalculation.

you cannot change the subscripts as that would change the substance itself. for instance, diatomic elements such as h2 only have the subscript two when a gas. another example would be so4, if you were to change the subscript, the element would no longer be sulfate.

we change the coefficients instead as that only changes the number of molecules rather than the substance itself.

hope this !