Atoms, Elements, Molecules, and Compounds Flashcards
Atom
The smallest particle of an element that can exist
Element
A pure chemical substance that cannot be physically split into a more simple substance. Each is made of one type of atom. Carbon, mercury, and hydrogen.
Molecule
The smallest particle of a substance that can exist. It is composed of two or more atoms.
Compound
A substance of atoms from two or more elements
Proton
A particle of matter that has a positive electrical charge and founding nucleus of an atom
Neutron
A particle of matter that has no electrical charge and is found in the nucleus of an atom
Electron
A particle of matter that has a negative electrical charge and travels around the nucleus of an atom
Atomic Number
= the number of protons in an element’s atoms. The top number in the element box.
Mass Number
The number of protons plus neutrons. The bottom number is in the element box.
Chemical Symbol
A one or two letter representation of an element
Subscript
Tiny number to the right of the element symbol. Tells you how many atoms of that element