Which statements are true? na+ is formed from the reduction of na(s). the oxidation number for is 0. the oxidation number for cu(s) is +2. zn2+ is formed from the oxidation of zn(s). a reducing agent gains electrons. an oxidizing agent gains electrons?

Following are True among given options;

1) The oxidation number for Hg(l) is 0:
                                                            It is correct as Mercury is present in its standard state and has a zero oxidation number.

2) Zn⁺² is formed from the oxidation of Zn (s):
                                                            This statement is correct as an element when looses electron gets positive charge. In this case the oxidation number of Zn has changed from 0 to +2, hence, it has lost 2 electrons and is oxidized.

3) An oxidizing agent gains electrons:
                                                           This statement is correct because Oxidizing agents are those compounds which gains electron from other substance making them oxidized and getting themselves reduced.

Not a  mixture of two common elements that can be separated by physical means.