atoms,elements/molicules, 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. barbon,mercury and hydrogen are examples.
Molecule
The smallest particle of a substance that can exist. It is composed of two or more atoms.
Compound
A substance made of atoms from two or more elements
Proton
A particle of matter that has a positive electrical charge and found in the nucleus of an atom.
Neutron
A particle of matter that has no electrical charge and 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 elements atoms. Top number in the element box.
Mass number
Number of protons plus neutrons. Bottom number 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.