Atoms Elements Molecules, and compounds Flashcards
Atoms
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 are examples
Molecule
the smallest particles of a substance that can exist. it is composed of two pr more atoms
Compound
A substance made of atoms from two ore more elements
Proton a
Neutron
a particles of matter that has no electrical charge and found in the nucleus of an atom
Electron
A particles of matter that has negative electrical charge and travels around the nucleus of an atom
Atomic number
=the number of protons in an element 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