What are some other facts about scientific notation?
The use of the word "other" implies that you already know of some facts about scientific notation. But you have not specified what. Unfortunately, we have not yet mastered the art of internet-based telepathy so we have no idea which facts you know and so which ones would be considered other.
What is the scientific notation for 900.000?
is that 900,000(nine hundred thousand) or 900(nine hundred)? Both here's both:
9 x 10 to the 5th power= 900,000.
9 x 10 to the 2nd power= 900.
How do you write standard notation to scientific notation and vice versa?
They are the same so you do nothing!
Why is scientific notation especially useful in earth science?
Because it deals in some very large and very small numbers.