Order the masses from smallest to largest

Can someone please tell me if this right.

1.  7.86 × 10⁴ g

2.  7.86 × 10⁴ kg

3.  1.989 × 10¹³ mg

4.  1.989 × 10²⁸ kg

5.  1.989 × 10³³ g

Explanation:

The easiest way to make sure you have the right answer is to convert all units to the same unit.

A.  1.989 × 10¹³ mg = 1.989 × 10¹⁰ g

B.  7.86 × 10⁴ g

C.  1.989 × 10³³ g

D.  7.86 × 10⁴ kg = 7.86 × 10⁷ g

E.  1.989 × 10²⁸ kg = 1.989 × 10³¹

The correct order is B < D < A < E < C

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

c) should be the answer.