Final answer:
The correctly written numbers in scientific notation from the provided options are B. 3.4 x 10^-8 and C. 2.12 x 10^-4 as they meet the criteria of the significant figure being between 1 and 10 and accompanied by a power of 10.
Step-by-step explanation:
The question you've asked pertains to identifying which number is correctly written in scientific notation. Proper scientific notation requires that the number be written as a product of a number between 1 and 10 and a power of 10. The numbers that are correctly written in scientific notation are option B and option C. Let's review each option:
- A. 10.3 x 10^4 - Incorrect, because 10.3 is not between 1 and 10.
- B. 3.4 x 10^-8 - Correct, because 3.4 is between 1 and 10 and it's multiplied by a power of 10.
- C. 2.12 x 10^-4 - Correct, because 2.12 is between 1 and 10 and it's multiplied by a power of 10.
- D. 0.18 x 10^5 - Incorrect, because 0.18 is not between 1 and 10.
Options B and C are correct and properly expressed in scientific notation.