the mass of an average grain of table salt in a sample is about 3x10^-4, and the mass of an average grain of rock salt in a sample is about 1.2x 10^- 2, convert both masses to standard notation

standard notation means in the number written in only number digits.

- to convert these multiply the two numbers given. FYI these are given in scientific notation, which is used so that numbers are easier to write.

remember: if the exponent is negative, you have move the decimal to the right. whereas, if the exponent is positive, you have to move the decimal to the left.

3 X 10^-4 --> move 4 places to the right.

answer - table salt: 0.0003

1.2 X 10^-2 --> move 2 places to the right.

answer - rock salt: 0.012

the formula would be mgso4

mgso[subscript]4

i believe it is-

d.) gravity pulled particles of dust and gas together to form planets.