What is Matter?
What is anything that has mass and takes up space?
Matter
What is an atom?
The smallest particle that makes up matter
What is a molecule?
Two or more atoms chemically bonded together
What is a physical change?
A change that does not form a new substance
Is dissolving sugar in water a physical or chemical change?
Physical change
Give two examples of matter.
Any valid examples (e.g. water, air, rock, table)
What is an element?
A pure substance made of only one type of atom
What is a compound?
A substance made of two or more different elements chemically bonded
What is a chemical change?
A change that forms a new substance
Is rusting iron a physical or chemical change?
Chemical change
Is air considered matter? Explain why.
Yes, because it has mass and takes up space
Give an example of an element.
Any valid example (e.g. oxygen, gold, carbon)
Give an example of a compound.
Any valid example (e.g. water, carbon dioxide)
Give one example of a physical change.
Any valid example (e.g. melting ice, cutting paper)
Is a compound or mixture easier to separate? Why?
Mixture, because it is not chemically bonded
Why is light NOT considered matter?
Because it has no mass and does not take up space
Why can an element not be broken down into simpler substances?
Because it contains only one type of atom
What is the difference between a molecule and a compound?
A molecule can be same or different atoms; a compound must have different elements
Give one example of a chemical change.
Any valid example (e.g. burning, rusting)
Classify: Oxygen gas (O₂) — element, compound, or mixture?
Element
Explain how mass and volume help define matter.
Matter has mass and occupies space (volume)
Explain the difference between an atom and an element.
An atom is a single particle; an element is a substance made of one type of atom
Why do compounds always have fixed ratios of elements?
Because atoms join together in specific numbers when they chemically bond.
Explain how you can tell the difference between a physical and chemical change.
Chemical changes form new substances; physical changes do not
A student says “all molecules are compounds.” Are they correct? Explain.
A molecule is any group of atoms chemically bonded together.
A compound is a type of molecule that contains different elements.