Btw this a 2 question test there will be 2 things to answer
william finds a piece of pure iron in his garden. after a few days, the iron begins to rust. what are the two types of substances involved in the rusting process of iron?
iron is
a a compound
b an element
c a mixture

with one kind of atom that combines with oxygen from the air to form rust (iron oxide). rust contains two types of atoms, which means it is
a a compound
b an element
c a mixture

Askydiver weighing 140 lb (including equipment) falls vertically downward from an altitude of 19,000 ft and opens the parachute after 18 s of free fall. assume that the force of air resistance, which is directed opposite to the velocity, is of magnitude 0.55|v| when the parachute is closed and is of magnitude 14|v| when the parachute is open, where the velocity v is measured in ft/s. assume that acceleration due to gravity has magnitude 32 ft/s/s; remember that weight is the product of mass and gravitational acceleration. (a) find the speed of the skydiver when the parachute opens. (b) find the distance fallen before the parachute opens. (c) what is the limiting velocity vl after the parachute opens? (d) determine how long the sky diver is in the air after the parachute opens. (e) plot the graph of velocity versus time from the beginning of the fall until the skydiver reaches the ground.

Calculate the ratio of h+ ions to oh– ions at a ph = 6. find the concentration of h+ ions to oh– ions listed in table b of your student guide. then divide the h+ concentration by the oh– concentration. record this calculated ratio in table a of your student guide. compare your approximated and calculated ratios of h+ ions to oh– ions at a ph = 6. are they the same? why or why not? record your explanation in table a. what is the concentration of h+ ions at a ph = 6? mol/l what is the concentration of oh– ions at a ph = 6? mol/l what is the ratio of h+ ions to oh– ions at a ph = 6? : 1

One form of energy can be another type of energy. a. created to form b. transformed into c. destroyed and then created to form