Sr is the most reactive. Correct me if I'm wrong :/
Explanation;
Writing scientific notation :
- Move the decimal to the left side until single digit of number remains before the decimal.
- Then we will count the number of times we moved the decimal. Write this number as the exponential power of number '10'.
- For Example:

Radius of the sun = 696,000.0 kilometer

Radius of the sun can also be written as =
Size of bacterial cell =
millimeter

Size of bacterial cell can also be written as = 
Answer:
8083.8ml x 1 L/1000ml x 1mole/ 24L = 194.01 moles
Explanation:
We use acids and bases in everyday life for cooking and cleaning