Explanation:
Pure subsance is a substance that is made up of only one type of particle - each piece is the same throughout.
Being present before the reaction but not after means it's no the same (it couldve evaporated)
It it important because it makes people wonder how things work and are made which makes it so they want to move forward with experiments <span />
A change of state (which is a physical change) can cause gas.
A. an ion
The atom gains a net electrical charge if the number of protons and electrons are not equal which makes it an ion.
Answer:
The water molecules slow down, stronger attractions form between them, and the molecules are pulled closer together.
Explanation:
In solids the packing of the particles is closer and tighter thus increasing the intermolecular attraction. This makes solids rigid with a definite shape, size and volume. On the other hand in liquids the packing of the particles is loose thus decreasing the intermolecular attraction. This makes liquids able to flow, and takes the shape and volume of the container in which they are placed.
