Definitely not D i would guess A or B
Answer: Scientific notation- 
Explanation: I got this by moving the decimal, so that there is one non-zero digit to the left of that decimal point. Tip- The number of decimal places you move will be the exponent on the 10.
Moved right- Negative
Moved left- Positive
One single covalent bond, hope this helps!
Answer:
i honetly dont thing anyone knows that so look it up
Explanation: