Fill In The Blanks

I have Sharing for the first blank and Single for the second.

A _______ pair of valence electrons consitutes a _______ covalent bond.

Shared/Double.

See http://www.chemguide.co.uk/atoms/bonding/doublebonds.html

I would have gone with shared and single, also.
http://www.chemguide.co.uk/atoms/bonding/doublebonds.html

1,000*4,0000

To calculate 1,000 multiplied by 4,000, you can perform the following steps:

1. Multiply the 1,000 value by 4, which equals 4,000.
2. Multiply the result (4,000) by 4,000, yielding the final answer of 16,000,000.

Therefore, the answer to 1,000 multiplied by 4,000 is 16,000,000.