In order to express this amount in scientific notation, we have to take the first digit:
![400,000,000,000,000=4\cdot100,000,000,000,000](https://img.qammunity.org/2023/formulas/mathematics/college/czz7chas3xqbqdz0dj9962vurqaitrq71l.png)
Then, for the multiple of 10, we count the number of zeros as:
![\begin{gathered} 10=10^1 \\ 100=10^2 \\ 1,000=10^3 \\ 1,000,000=10^6 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/z7cdqjr0dqyjsrzfmjjfup8cfqn4u8lcms.png)
If we count the zeros, we have 14 zeros, so we can write:
![\begin{gathered} 100,000,000,000,000=10^(14) \\ 4\cdot100,000,000,000,000=4\cdot10^(14) \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/90tqu8dn7x7gwmchf4ozenfqhl0n2fn172.png)
The answer is C) 4 * 10^(14)
2) We have to divide the number of gallons of water in the Atlantic ocean (A=2*10^16) by the number of gallons in the Lake Ontario (O=4*10^14).
We can do this as:
![undefined]()