What is necessary to write a number in scientific notation? Select all that apply. A. One factor is greater than 10. B. The number is written as the product of three factors. C. The number is written as the product of two factors. D. One factor is a power of 10 with the exponent being an integer. E. One factor is greater than or equal to 1 and less than 10. OF. One factor is a power of 10 with the exponent being a decimal.