Science:Chapter6 definitions Flashcards
What is an atom?
*Atom is the smallest particle of matter.
*Atoms of different elements are different sizes.
*Atoms are not made or destroyed in chemical reactions.
What is a molecule?
*A molecule is a group of atoms joined together.
*They can take part in chemical reactions.
*The atoms in a molecule do not have to be the same as each other.
What is an element?
*Element is a substance made up of only one type of atom.
What is a physical change?
A physical change is when atoms form in a new way to give us a mixture but do not create a new substance.
What is a chemical change?
A chemical change is when atoms arrange in a different way to give us a new substance called a compound.
What is a substance?
A substance is matter that has the same make up and properties throughout.
What is a mixture?
A mixture is two or more different substances physically combined;the physical change is easily reversed.
What is a compound?
A compound is formed when two or more different elements combine together chemically.This change is very difficult to reverse and new substance is formed.
