I think it's call a magnet
Answer: (3) silicon
Explanation:
Element is a pure substance which is composed of atoms of similar elements.It can not be decomposed into simpler constituents using chemical reactions.Example: Silicon (Si)
Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.It can be decomposed into simpler constituents using chemical reactions. Example: ethane
, propanone
and water 
In order for things to dissolve they must dissolve in a solvent similar to them (polar and polar or nonpolar and nonpolar) Oil is nonpolar and vinegar is polar therefore oil wont dissolve in vinegar
The kinetic energies of the particles (atoms, molecules, or ions) that make up a substance or object.