Heeelllppp ppleeaassee which statement best describes a battery? identical cells are arranged in the same orientation to increase the energy output. identical cells are arranged in opposite orientations to reverse the half reactions. different cells are arranged in the same orientation to increase the energy output. different cells are arranged in opposite orientations to reverse the half reactions.

OXIDATION UNIT TEST

1. Which statement best explains why magnesium and chlorine combine in a 1:2 ratio?

A. Magnesium has two valence electrons, and chlorine can accept one electron in its outer shell

2. Hydrogen and nitrogen combine to form ammonia. When nitrogen and hydrogen bond, nitrogen pulls the electrons from hydrogen toward itself. Which statement about the reactants is correct?

C. Hydrogen is oxidized, and nitrogen is reduced.

3. C3H8 + 5O2 → 3CO2 + 4H2O + energy

Which type of reaction is shown?

C. combustion

4. Which phrase best defines a redox reaction?

D. a reaction in which electrons are transferred between different atoms

5. Which statement describes the process of oxidation?

D. Oxidation results in a loss of electrons, so the oxidation number increases.

6. Which chemical equation represents a redox reaction?

D. Fe2O3(s) + 2Al(s) → Al2O3(s) + 2Fe(l)

7. Which statement correctly describes the oxidation number of the manganese atom (Mn) in MnI2 and MnO2?

A. Manganese has an oxidation number of +2 in MnI2 and +4 in MnO2.

8. Br2(l) + 2NaI(aq) → I2(s) + 2NaBr(aq)

Which elements are oxidized and reduced in the reaction?

D. Iodine (I) is oxidized, and bromine (Br) is reduced.

9. Which action occurs at an electrode of a galvanic cell?

D. electron transfer

10. Which statement best compares a battery and a galvanic cell?

A. A battery’s source of power is a galvanic cell in which a redox reaction produces electrical energy.

11. Zn + 2H+ → Zn2+ + H2

2Al + 3Cu2+ → 2Al3+ + 3Cu

Which elements are oxidized?

A. zinc (Zn) and aluminum (Al)

12. 2Cr(s) + 3Cu2+(aq) → 2Cr3+(aq) + 3Cu(s)

Which half reaction occurs at the cathode?

B. 3Cu2+(aq) + 6e– → 3Cu(s)

13. Written

14. Written

15. Written

I hope this helps!

answer:

the answer is 6 valence electrons.

explanation:

valence is the # of electrons on the outer most shell of an atom.

oxygen has 6.

although, the valency of oxygen is 2, because it only needs to make 2 covalent bonds, or gain 2 electrons, to achieve the stable octet configuration of a noble gas.

that's it!

if you need further assistance, let me know: )

~ trueboss72