Need chemistry help please!!!!!!!!!!?

i need help for these 2 questions:

3. write each measurement in scientific notation.

a. the lenght of a football field, 91.4 meters.

b. the diameter of a carbon atom, 0.000 000 000 154 meters

c. the radius of Earth, 6 378 000 meter

d. the diameter of a human hair, 0.000 008 meter

e. the average distance between the center of the sun and the center of earth, 149 600 000 000 meters

and also help for this question.

4. solve each problem, and express each answer in correct scientific notation.

a. (4 x 10^7) x (2 x 10^-3)

b. (6.3 x 10^-2) / (2.1 x 10^4)

c. (4.6 x 10^3) - (1.8 x 10^3)

d. (7.1 x 10^-2) + (5 x 10^-3)

Need chemistry help please!!!!!!!!!!?

a. 9.14 x 10^1

b. 1.54 x 10^-10

c. 6.378 x 10^6

d. 8 x 10^-6

e. 1.496 x 10^11

and i cant do the second part.

Need chemistry help please!!!!!!!!!!?

second part:

a) 8*10^4

b)3*10^-6

c)2.8*10^3

d)7.6*10^-2