Molecules can be made of atoms of the same element only different elements only the same or different elements

Molecules can be made of the atoms of same element as well as of the different elements.

Explanation:

H2 is called a molecule because it is made up of atoms of same elements H.

Also, H2O is called a molecule as it is made up of atoms of different elements H and O.

it takes about 30 days for it to break down

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                                         : )