1. Why do different substances have different properties? 2. Describe in detail what everything is made of?
3. Explain macro and micro scale.

Tin has ten stable isotopes. the heaviest, 124sn, makes up 5.80% of naturally occuring tin atoms. how many atoms of 124sn are present in 82.0 g of naturally occurring tin? what is the total mass of the 124sn atoms in this sample?

Molecular iodine, i2(g), dissociates into iodine atoms at 625 k with a first-order rate constant of 0.271 s−1. part a part complete what is the half-life for this reaction?

Which substance—wood or silver—is the better thermal conductor? a thermal conductor is a material that requires very little heat energy to change its temperature. explain your answer.