Atoms, Particles and Molecules

Atoms are the smallest pieces of matter; they are made of particles (protons and electrons). When atoms are grouped together, the groups are called molecules, which are the smallest bits of compounds.

By way of example, within the element copper, a copper atom is the smallest piece of copper that exists. Hydrogen is an element; two hydrogen atoms and one oxygen atom combine to form a molecule of water, which is a compound.

Element - a basic substance that can't be simplified, such as copper
Atom - the smallest amount of an element, such as copper atom
Molecule - two or more atoms that are chemically joined together, such as hydrogen or oxygen
Compound - a molecule that contains more than one element, such as water

Weighing Atoms

Did you know we can now weigh a single atom? European researchers have built a device that can do just that. It may ultimately allow scientists to study the progress of chemical reactions, molecule by molecule. They believe they can push the technology to detect the mass of a single nucleon - a proton or neutron.

Carbon nanotubes are ultra-thin fibres of carbon made from thin sheets of carbon only one atom thick, known as graphene, and rolled into a tube only a few nanometres across. Even the thickest is more than a thousand times thinner than a human hair and are 1000 times stronger than steel. And I thought only Superman was stronger than steel.