Pure substances and mixtures Flashcards
What is a mixture?
2 or more substances that are NOT chemically combined together.
What is a molecule?
2 or more atoms held together by chemical bonds.
What is a compound?
2 or more different elements held together by chemical bonds.
What is a pure substance?
A pure substance consists only of one element or only one type of compound.Never mixed with any other substance.
How do you check if a substance is pure or impure?
Pure substances melt at a specific fixed temperature and it has a specific fixed boiling point but impure substances melt at a range of temperature.
What does it mean if a pure substance only has one type of atoms throughout.
That means the composition cannot change. That’s what makes an element a pure substance.
What does it mean if a pure substance only has repeating compounds throughout.
That still means the composition will not change even if it’s not one type of atom because they are held together firmly in place and have a repeating pattern.
