Read the following chemical equation. Fe + 02 - Fe2O3
Which of the following fractions can be used for the mole ratio to determine the mass of Fe from a known mass of Fe2O3?

4/2

3/2

2/3

2/4

Which of the following pairs of elements belong to the same groupa. h and he b. li and bec. c and pb d. ga and ge

Use examples from the article to explain one positive and one negative effect that chemistry has had on society.

Joe shines white light into a bowl half full of water at an angle of incident of 27.5°. calculate the angle of refraction in the water given the indices of refraction for air and water are 1.00 and 1.36, respectively.