To how many significant figures should each answer be rounded? a) (6.62610^-34 js)(2.997910^8 m/s) / 4.07010^-7 m = 4.880610663391*10^-19 j(unrounded)b) (6.02210^23 atoms/mol)(0.589 g) / 20.18 g/mol = 1.75810^22 atoms (unrounded)

a) after rounding: 4 significant figures.

b) after rounding: 3 significant figures.

Step-by-step explanation:

Significant figures are the number of needed place values for accuracy. The product or quotient of numbers with significant figures must be rounded to the least amount present within the problem.

a) (6.62610^-34 Js)(2.997910^8 m/s) / 4.07010^-7 m = 4.880610663391*10^-19 J

4.880610663391*10^-19  rounds to 4.880 * 10^-19 since the least number of significant digits is 4 within the problem.

b) (6.02210^23 atoms/mol)(0.589 g) / 20.18 g/mol = 1.75810^22 atoms

1.75810^22 rounds to 1.76 *10^22 since the least number of significant digits within the problem is 3.

the 8 in 8,420 is in the thousands place so it's value is 8 thousand.

the 8 in 6,870 is in the hundreds place so it's value is 8 hundred.

divide 8000 by 800 to find the answer:

8000 / 800 = 10

the 8 in 8,420 is 10 times greater than the 8 in 6,870

see below

step-by-step explanation:

x+2> 6

subtract 2 from each side

x+2-2 > 6-2

x > 4

there is an open circle at 4 since is it is greater than and the line goes to the right