smallest particle which an element can be divided and still be the same substance. they make up elements.and they are called the BUILDING BLOCKS OF LIFE.(elements combine to form compounds).Diamter (3 hundred-millionths)
Dalton's atomic theory
1.all substances made up of atoms.atoms are small particles that cannot be created,divided or destroyed.
2.atoms of same elements are identical, atoms of diff. elements are diff.
3.atoms join with other atoms to form new substances.
small particles inside an atom, negative charge.(-)
they are located on the electron clouds/levels/shells.
used a gold foil experiment to discover there was a small massive thing inside of an atom.
the center of an atom. (Most of the atom is made up of electron clouds.)most mass is found in the nucleus connection to the neutrons & protons.
exact path of an electron cannot be predicted therefore we call them e-clouds.
Inside of an atom:
(+) is its charge.
to find the # of proton we look at the atomic # located in upper right .
located:outside of the nucleus in electron cloud or shell.
(-)is its charge.
to find the # of electron =# of proton.
-an atom with the same # of protons(so still the same element) but diff.# of neutrons.
-some are unstable so they are radioactive.
-most isotopes share same properties.
weighted average of all the naturally occurring isotopes so this explains why it is a nonradioactive.