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 simpler substance, Each is made of one type of atom. Carbon, mercury and hydrogen and examples.
Molecule
the smallest particles a substance that can exist. It is composed of two or more atoms.
Compound
a substance made of atoms form two or more different 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 ha 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 element’s atoms. Top number in the element box.
Mass Number
Number of protons plus neutrons. Bottom number in the element box.
Chimcal sybol
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.