Any sample of an ELEMENT is made of only one type of atom.
Here are some elements:
-- Hydrogen, Helium, Neon
-- Carbon (lead in a pencil, also diamonds)
-- Oxygen, Nitrogen, Argon (All mixed together in air, but not hooked up with other atoms)
Other elements you may have heard of:
-- Silver, Gold, Copper, Iron, Lead, Aluminum, Silicon, Chlorine, Calcium, Titanium, Nickel, Tin, Platinum, Mercury, Radium, Uranium
