Chemistry key terms Flashcards
What is an atom?
The smallest part of an element
that can exist.
What is a proton?
Positively charged particle
found inside the nucleus of atoms.
What is a neutron?
Neutral particle found inside
the nucleus of atoms.
What is an electron?
Negatively charged particle
found in energy levels (shells)
surrounding the nucleus inside atoms.
What is the nucleus?
Central part of an atom
containing protons and neutrons.
What are the shells?
The region an
electron occupies surrounding the
nucleus inside an atom
What is the atomic number?
Number of protons in an atom.
What is the mass number?
The number of protons plus the number of neutrons.
What is an isotope?
The same element that has an atoms with the same number
of protons, but a different number of
neutrons.
What is a molecule?
2 or more atoms held together by chemical bonds.
(Molecules can contain different elements held together).
What is a compound?
Substances that contain 2 or more different elements.Held together by chemical bonds.
What is a mixture?
Two or more substances not chemically combined together.
What is a pure substance?
A liquid that only contains one type of compound or element.
