6.79 x 10⁶
<h3>Further explanation </h3>
Scientific Notation consists of 2 parts
1. the first part: the first digit followed by the decimal point
2. The second part: the power of 10 (the exponents).which shows the number of digits after the decimal point
To add/subtract, the exponents must be the same and then add/subtract the coefficient
- convert the largest exponent

- subtract the coefficients

Sodium Flouride
Magnesium Nitrate
Calcium Phosphate
Sodium Oxide
Lead Iodide
Copper Sulphate
I've answered another one of your questions with the content of how to work these out
Answer:
65,000 g/mol, 43,000g/mol and 22,000 g/mol.
Explanation:
The explanation can be found in the attachment