Lewis Dot Structures & Covalent Bonding Gilbert Newton Lewis (surrounded by pairs of electrons)

Lewis-Dot Structures Find out which group (column) your element is in. This will tell you the number of valence electrons your element has. You will only draw the valence electrons.

Groups - Review Group 8 = 8 electrons Group 1 = 1 electron Except for He, it has 2 electrons Group 2 = 2 electrons 3 4 5 6 7 Each element in a group has the same number of electrons in their outer orbital, also known as “shells”. The electrons in the outer shell are called “valence electrons”

C Lewis-Dot Structures Write the element symbol. Carbon is in the 4th group, so it has 4 valence electrons. Starting at the right, draw 4 electrons, or dots, counter-clockwise around the element symbol. C

Lewis-Dot Structures Try these elements on your own: H P Ca Ar H

Lewis-Dot Structures Try these elements on your own: H P Ca Ar P

Lewis-Dot Structures Try these elements on your own: H P Ca Ar Ca

Lewis-Dot Structures Try these elements on your own: H P Ca Ar Ar

Lewis-Dot Structures H He:            Symbols of atoms with dots to represent the valence-shell electrons 1 2 13 14 15 16 17 18 H He:            Li Be  B   C   N  : O  : F  :Ne :                   Na Mg  Al  Si  P : S :Cl  :Ar :       

F K In an IONIC bond, electrons are lost or gained, resulting in the formation of IONS in ionic compounds. F K

K F

K F

K F

+ _ K F

K F _ + The compound potassium fluoride consists of potassium (K+) ions and fluoride (F-) ions

K F _ + The ionic bond is the attraction between the positive K+ ion and the negative F- ion

atoms still want to be like a noble gas (the octet rule). In covalent bonding, atoms still want to be like a noble gas (the octet rule). But rather than losing or gaining electrons, atoms now share an electron pair.

Covalent bonding example: Carbon = H

H H H C H Covalent bonding example: Carbon now has an octet. All hydrogen atoms now have 2 electrons H