Chemistry Scavenger Hunt?

Question

I have a chemistry scavenger hunt project and I need help finding an example of the following and also the reasoning behind it. Illustrate the difference between weight and mass, a hydrocarbon, a covalent molecule, ions, a material other than water that undergoes sublimation, and describe the difference between fusion and fission-- diagram and models may be used

Answer 1

Its a good thing you can bring in a diagram, otherwise your last request would require a nuclear bomb.

Here are some ideas

covalent molecule - sugar
sublimating material - iodine
hydrocarbon - candle
ions - salt

Answer 2

F=ma
F=GmM/r^2
A satellite in vacuum free fall is weightless but massed.

Paraffin (canning section of your supermarket).

Paraffin, polyethylene.

Table salt.

Dry ice, camphor, naphthalene, cubane.

Google it.