chemguide: CIE A level chemistry support: Learning outcomes 1.3

Tags

Top Highlights

• outermost shell is sometimes called the valence shell. This is the shell where the electrons are involved in reactions.

• sub-shell covers the slight differences in energy of various orbitals in each of these levels

• principle quantum number (n). This is the posh name for the over-all energy level

• electrons in the 1-level, have a principle quantum number of 1. In the 3-level they all have the principle quantum number of 3.

• When we write electronic structures for atoms or ions, electrons always go into the lowest energy levels available

• ground state of the atom.

• possible to excite electrons to higher levels by putting in energy

• excited state,

• fall back to their original ground state releasing energy again.

• free radicals as any species with one or more unpaired electrons

• can include atoms, ions and molecules.

• chlorine radical is just an isolated chlorine atom which has 7 electrons in its outer level.