Remembering the formula for slag
Slag is CaSiO3.
This may look like a slag heap but when you look at it closely, you can see it is made up of Casio calculators! Casio (CaSiO) calculators with a tree = CaSiO3
From the formula, you should be able to work out that slag contains:
Oxygen (O)(ate) Definition of ate
Therefore, the compound is actually calcium silicate.