Answer: The mass of the sand is greater than the mass of the salt.
Step-by-step explanation: Scientific notation is a way of writing numbers that are very large or very small. It is written in the form a x 10^b, where a is a number between 1 and 10 and b is an integer. For example, 300 can be written as 3 x 10^2 in scientific notation.
To compare the masses of the salt and sand grains using scientific notation, we first need to write them in scientific notation. The mass of the salt is 0.0006 grams, which can be written as 6 x 10^-4 grams. The mass of the sand is 0.009 grams, which can be written as 9 x 10^-3 grams.
Next, we compare the exponents. Since -3 < -4, we know that 9 x 10^-3 > 6 x 10^-4. This means that the mass of the sand is greater than the mass of the salt.
Hope this helps, and have a great day!