It is estimated that uranium is relatively common in the earth's crust, occurring in amounts of 4 g / metric ton. a metric ton is 1000 kg. at this concentration, what mass of uranium is present in 1.2 mg of the earth's crust?

The mass of Uranium present in a 1.2mg sample is

Explanation:

The ration between Uranium mass and total sample mass is:

For a sample of mass 1.2 mg, the amount of uranium is:

b would be the answer

answer would be letter choice (a),   a ball resting on a shelf. would be another example of potential energy   >   stored energy > not moving.

a ball spinning on a finger   >   kinetic energy > moving energy

a ball rolling on the ground   >   kinetic energy   > moving energy

a   ball flying through the air   > kinetic energy   >   moving energy

hope that                                         : )