Chemical Bonding
From ZuluNotes - Free Leaving Cert Notes
A compound - is a substance made up of two or more different elements chemically combined together. the octet rules - states that - when bonding occurs atoms tend to reach an electron arrangement with eight electrons in the outermost shell.
Exceptions - 1.transition metals have more or less then 8 electrons in their outermost shell. 2.H,HE,LI tend to achieve stability with 2 electrons in outer most shells.
Ionic bonding - -> an ion is a charged atom or a group of atoms. -> an ionic bond is the force of attraction between oppositely charged ions in a compound. -> an ion is formed when an atom gans or looses an electrons.
Group 1 (alkali metals)-lose 1 electron. Group 2 ( alkaline earth metals)- lose 2 electrons. -> when an atom loses electrons it becomes positively charged - called cations.
Group 6 -> gain 2 electrons group 7 (halogens)-> gain 1 electrons When an atom gains electrons it becomes negatively charged- called anions!
Love them or loath them remember: cats are positive!
