40.0 g ( 1 mole ) --------------- 6.02x10²³ molecules
? ? --------------------------- 2.90x10²² molecules
mass = 2.90x10²² * 40.0 / 6.02x10²³
mass = 1.16x10²⁴ / 6.02x10²³
mass = 1.9269 g
hope this helps!
The correct answer is actually
B) energy that flows from warmer objects to cooler objects.
because temperature is a measure of the average amount of energy possessed by an object due to the random motions of its particles. Heat is the energy that flows from warmer objects to cooler objects. Heat cannot flow in the opposite direction.
The chemical make-up changes.