How do we know that heat is transferred from the sun to earth by radiations?

Iknow the answer to 13 is b and 14 is d. i just need to know why the correct answers are correct

Chromium(iii) sulfate is a transition metal compound containing the metal chromium and the polyatomic ion sulfate. the oxidation state of chromium in this compound is , and the chemical formula of the compound is ( ) . reset next

Iron (fe) reacts with copper sulfate (cuso4) to form iron (ii) sulfate. in this reaction, cu2+ gains electrons to form cu. which statement is true about this reaction? fe(s) + cuso4(aq) → feso4(aq) + cu(s)