Actinium
Actinium is a radioactive silvery-white metal and the first member of the actinide series. It glows blue in the dark due to its radioactivity and was the first non-primordial radio…
Elements
Pure substances that cannot be broken down by chemical means
118 chemicals in this category
Aluminium
Aluminium is a silvery-white lightweight metal, atomic number 13, the most abundant metal in Earth crust. Forms thin protective oxide layer preventing corrosion. Highly malleable, …
Americium
Americium is a synthetic radioactive actinide. Americium-241 is widely used in ionisation-type smoke detectors, making it the most common artificial element encountered in everyday…
Antimony
Antimony is a lustrous, silvery metalloid, atomic number 51. Known since antiquity (kohl eye makeup was Sb2S3). Brittle and flaky. Used in alloys for hardening lead. Antimony triox…
Argon
Argon is a colourless, odourless noble gas, atomic number 18, the most abundant noble gas in Earth atmosphere (0.934%). Chemically inert with no known stable compounds. Produced by…
Arsenic
Arsenic is a metalloid, atomic number 33. A notorious poison since antiquity. Occurs naturally and from industrial contamination of groundwater. Also has industrial uses in semicon…
Astatine
Astatine is a radioactive halogen, atomic number 85. The rarest naturally occurring element in Earth crust (total amount ~31 grams at any time). All isotopes are short-lived. At-21…
Barium
Barium is a soft, silvery alkaline earth metal, atomic number 56. Highly reactive - reacts with water and air. Barium sulfate (BaSO4) is uniquely insoluble and non-toxic - used as …
Berkelium
Berkelium is a synthetic radioactive actinide produced by bombarding americium with alpha particles. It is named after Berkeley, California, where it was first synthesised in 1949.…
Beryllium
Beryllium is a hard, grey, lightweight alkaline earth metal, atomic number 4. Highly toxic - inhalation causes chronic beryllium disease (berylliosis). Found in beryl minerals (eme…
Bismuth
Bismuth is a brittle, silvery-pink post-transition metal, atomic number 83. Has the highest natural diamagnetism of any element. Its crystals form beautiful hopper-shaped formation…
Bohrium
Bohrium is a synthetic radioactive transactinide element named after Niels Bohr. Expected to behave similarly to rhenium. First synthesised in 1981 in Darmstadt, Germany.
Boron
Boron is a metalloid, atomic number 5. Does not occur as free element - found in borax and boric acid. Forms wide range of covalent compounds. B-10 is an excellent neutron absorber…
Bromine
Bromine is a reddish-brown liquid halogen, atomic number 35. One of only two elements that are liquid at room temperature (the other being mercury). Has a strong, unpleasant suffoc…
Cadmium
Cadmium is a soft, silvery-white transition metal, atomic number 48. Highly toxic heavy metal and carcinogen. Mainly occurs as a by-product of zinc smelting. Historically used in n…
Caesium
Caesium is a soft, gold-coloured alkali metal, atomic number 55. Has the lowest ionisation energy and electronegativity of any stable element. The caesium atomic clock defines the …
Calcium
Calcium is a soft, grey alkaline earth metal, atomic number 20. Fifth most abundant element in Earth crust. Essential for life - major component of bones, teeth, shells. Calcium io…
Californium
Californium is a synthetic radioactive actinide and a very strong neutron emitter. It was first produced at the University of California, Berkeley in 1950. It has practical uses as…
Carbon
Carbon is a non-metal, atomic number 6, forming the basis of all known life. Allotropes include diamond, graphite, graphene, and fullerenes. Forms more compounds than any other ele…
Cerium
Cerium is a soft, silvery, ductile rare earth metal, atomic number 58. Most abundant lanthanide. Pyrophoric as powder or shavings - sparks when struck (used in lighter flints). Cer…