Which element in the given compounds has the highest oxidation state?C in CO2S in CaSO in O2S in SO3

The oxidation state of an element in a compound can be determined by the number of electrons it has lost or gained.

1. In CO2 (Carbon Dioxide), the oxidation state of Carbon (C) is +4. This is because Oxygen has an oxidation state of -2, and since there are two Oxygen atoms, Carbon must have an oxidation state of +4 to balance it out.

2. In CaSO4 (Calcium Sulfate), the oxidation state of Sulfur (S) is +6. This is because Oxygen has an oxidation state of -2, and since there are four Oxygen atoms, Sulfur must have an oxidation state of +6 to balance it out. Calcium has an oxidation state of +2.

3. In O2 (Oxygen), the oxidation state of Oxygen is 0. This is because it's a diatomic molecule of the same element, so no electrons are lost or gained.

4. In SO3 (Sulfur Trioxide), the oxidation state of Sulfur (S) is +6. This is because Oxygen has an oxidation state of -2, and since there are three Oxygen atoms, Sulfur must have an oxidation state of +6 to balance it out.

So, the element with the highest oxidation state in the given compounds is Sulfur (S) in CaSO4 and SO3 with an oxidation state of +6.