What is an Ion? • It is a charged atom • Elements in the periodic table are written in their neutral form (+ve and –ve charges cancel each other out and have overall charge of 0) • i.e. meaning that the total number of protons (the atomic number) is equal to the total number of electrons • When an element is in ionic form, it means that it is no longer has a 0 charge, but is either +ve or -ve
What happens when atoms become ions • When an neutral atom looses an electron, it takes on a positive charge! • It has more p+ than e-! • This happens to metals! • When an neutral atom gains an electron, it takes on a negative charge! • It has more e- than p+! • This happens to non-metals!
Metals as ions • When metals are in ionic form, they have an overall positive charge • Remember, elements in groups 1-3 have only 1,2 or 3 valence electrons • The easiest way for these elements to have a full electron shell is to give away these valence electrons • Metals donate their electrons to non-metals, forming a stable compound
Non-metals as ions • When non-metals are in ionic form, they have an overall negative charge • Remember, elements in groups 4-7 are missing 4,3,2 or 1 electron to get a full electron shell • The easiest way for these elements to have a full electron shell is to get electrons • Non-metals accept electrons from metals, forming a stable compound
What happens in Chem. Rnxs? • Metals will donate e- to non metals • Metals → +vely charged, for they will have more p+ than e-! • Non-metals will accept e- from metals • Non-metals → -vely charged, for they will have more e- than p+! • Elements in Group 8 will not react, for they have a full electron orbital and are already stable
Valence • It is the total number of bonds an element can make • It also has to do with the number of valence electrons an element has • i.e, if an element has only 1 valence electron, it can only make one bond (only has one electron to loose) • i.e. if an element has 7 valence electrons, it too can only make one bond, since it can only accept one more electron
Valence • Chemical bonds always has to do with the transfer of electrons from elements to elements to form stable compounds • **Note: Group 4’s ionic charge is -4, since it is easier for elements in this group to gain four electrons than to remove four electrons**