I was asked to give the name of the compound CaSi on a practice exam, which I thought was weird because as far as I knew Ca was always +2 and the periodic table kinda suggests that Si would be -4. So I didn't know how the compound CaSi would exist.
So I just said Calcium (IV) Silicide and handed it in, even though I was pretty sure Calcium didn't have multiple oxidation numbers.
And then they said the right answer was Calcium Silicide and I didn't even need the (IV), so now I'm really confused.
How can CaSi exist, and why don't I need the (IV)?
Any help will be really appreciated!
(I have an exam on Friday
)
Confused again,
~Jules~