Final answer:
The number 1,000,000,000 written as a power of 10 is 10^9, which indicates that the decimal point has been moved 9 places to the left to convert the number into scientific notation.
Step-by-step explanation:
To write 1,000,000,000 as a power of 10, it is equal to 10 multiplied by itself 9 times, which can be represented as 10^9. The number 1,000,000,000 can be written as a power of 10 by determining how many times the decimal point must be moved to the left to get a number between 1 and 10. In this case, moving the decimal point 9 places to the left turns 1,000,000,000 into 1. So, 1,000,000,000 is equal to 1 x 10^9, which makes the correct answer 10^9.