To identify which numbers are in scientific notation, we look for the form \( a \times 10^n \), where \( a \) is a number (the coefficient) that is typically between 1 and 10 (inclusive of 1 but exclusive of 10) and \( n \) is an integer (the exponent).
Let's examine each number:
- 0.3 x 10⁵ - This is not in proper scientific notation, as the coefficient (0.3) is less than 1.
- 5 x 10⁻⁸ - This is in proper scientific notation, as the coefficient (5) is between 1 and 10.
- 67.8 x 10⁻¹⁵ - This is not in proper scientific notation, as the coefficient (67.8) is greater than 10.
- 7.9 x 10¹⁰ - This is in proper scientific notation, as the coefficient (7.9) is between 1 and 10.
- 16.2 x 10¹⁴ - This is not in proper scientific notation, as the coefficient (16.2) is greater than 10.
So, the numbers that ARE in scientific notation are:
- 5 x 10⁻⁸
- 7.9 x 10¹⁰