Electrons exist in energy states within the atom (called orbitals by chemists). Generally, the further away from the nucleus these states are, the higher the potential energy of the electron in that state. When an electron is 'free' of the nucleus' influence it is said to have zero potential energy...

An atom is the smallest chemically indivisible part of an element - that means you can't split it by chemical (or physical) means into anything smaller - it takes a nuclear reaction to do it! All of the different types of atom known to exist in the universe are listed in...

By accelerating particles to very high energies and smashing them into targets, or into each other physicists can unravel the forces acting between them. Accelerators come in two types, linear (see the LINAC) and...

At sea level the Earth's atmosphere is pushing on you from all sides with a pressure of 101,000 N/m2 (101 kPa). As you climb higher - away from sea level - that pressure decreases. This is because there is less air above you, weighing you down. We...

Even though we do not feel it, 101,000 pascals of pressure is pushing down on our bodies as we rest at sea level. Our body compensates for this weight by pushing out with the same force. As water is much denser than air, this pressure increases as we venture into the water. For every 10m we decend into the depths of the ocean one...

Read description: MossFossil range: Carboniferous[1] – recent PreЄ Є O S D C P T J K Pg N "Muscinae" from Ernst Haeckel's Kunstformen der Natur, 1904 Scientific classification Kingdom: Plantae Division: BryophytaSchimp. Classes [2] TakakiopsidaSphagnopsidaAndreaeopsidaAndreaeobryopsidaOedipodiopsidaPolytrichopsidaTetraphidopsidaBryopsidaMosses...

Read description: HornwortFossil range: 90–0 Ma PreЄ Є O S D C P T J K Pg N Upper Cretaceous (but see text) to recent Phaeoceros laevis (L.) Prosk. Scientific classification Kingdom: Plantae Division: AnthocerotophytaStotler & Stotl.-Crand.[1] Class: Anthocerotopsida Families & Genera Leiosporocerotaceae...

Read description: LiverwortsFossil range: 380–0 Ma PreЄ Є O S D C P T J K Pg N Mid-Devonian[1] to recent "Hepaticae" from Ernst Haeckel's Kunstformen der Natur, 1904 Scientific classification Kingdom: Plantae Division: MarchantiophytaStotler & Stotl.-Crand., 1977[2] emend. 2000[3] Classes and Orders ...