Chemistry

In a modern Periodic Table the elements are written in order of increasing atomic number, not increasing R.A.M. This leads to Periodic law which states…

Dobereiner’s “triads” (1829) where groups of three similar elements were made such as Li, Na, K; Ca, Sr, Bo; or Cl, Br, I This was…

Inter molecular forces are weak, so the molecules are not pulled very close together. More space between the molecules means that solid simple molecular compounds…

Simple molecules Most covalently bonded substances exist as simple small or medium sized molecules, rather than as giant structures. When simple molecules are heated moderately,…

Fullerenes are a recently discovered family of carbon allotropes in the form of spheres, tubes or flat planes with unusual and potentially useful properties. The…

Graphite (the “lead” inside pencils) is another allotrope of carbon. Each carbon atom is joined by strong covalent bonds to three others, forming sheets of…

Some elements (such as carbon and silicon) are most stable when each atom forms several covalent bonds to other atoms. This means that some of…

Ionic solids have no free electrons. Any charged particles (including ions) can carry electric current, but in an ionic solid the ions are trapped in…

In ionic solids, there are strong, electrostatic attractive forces between the positive and negative ions. To melt the solid, these very strong forces must be…

There are 14 different types of crystal unit cell structures or lattices are found in nature. However most metals and many other solids have unit…