1. Covalent Bonding Where sharing electrons is caring!

2. What is a Covalent Bond? • A covalent bond is when two or more non-metalatoms join together to form a molecule. • In a covalent bond atomsshare one or more electrons.

3. Properties of Covalent Bonds • These types of bonds are weak. • Therefore they have properties like: low boiling points and are soft or brittle. • Recall: Boiling Pt.=Temp. @ liquidgas. • Since they don’t have metals in them they don’tconduct electricity or dissolve in water.

4. How Do You Name Them? • We use prefixes that indicate the number of atoms. • 1. The first element in the formula keeps its name the same. • 2. The second element in the formula changes the ending of its name to “ide”. • 3. If there is more than one atom of the first element then we have to add the correct prefix. • 4. We have to add the correct prefix for the second element.

5. Let’s Try An Example • We are given the formula CF4 • Q: How can you tell if it is a covalent or ionic compound? • A: It is covalent because it is two non-metals. • A:Because the first element is a non-metal. • To name it follow the rules off the previous slide: • Identify the name of the first element is by looking at the symbol and finding its name on the PT. • Write the name of this element down. • Repeat steps 1+2 for the second element but change the ending of its name to “ide”.

6. Let’s Try An Example • We are give the formula CF4 • To name it follow the rules off the previous slide: • Look at the number of atoms of the first element. • Choose the correct prefix from the table. • Add this prefix to the beginning of the name. • Repeat steps 4-6 for the 2nd element. • So far we have: Carbon tetra fluoride If the 1st non metal has only one atom = no prefix The 2nd non-metal ALWAYS gets a prefix

7. Getting Covalent Formulas • Look at the name of the compound to: • 1. Identify the elements in the name and write down their chemical symbols from the PT. • 2. Look to see if there are any prefixes in front of the chemical names. • 3. Write down the correct number of atoms according to the prefixes below the chemical symbols.

8. Covalent Formula Practice • Let’s say we are given: DicarbonMonoxide • First we must identify the two elements and write down their symbols: C and O • Next we check for prefixes: • There is a Di =2 in front of carbon so it’s C2 • There is a Mono=1 in front of oxygen so it’s O • The completed formula = C2O

9. Diatomic Elements • Are elements which bond to themselves. Making a general formula of X2 • They are an E.G. of covalent bonding. • An acronym to remember the diatomic elements is Mr. H.O.F.Br.I.N.Cl. (Symbols for elements that do this.)

10. HOFBrINCl Formulas and Naming • The name stays the same as on the P.T. followed by the word “gas”. • E.G. If you were asked to name O2 : • The name would be oxygen gas. • This is the same of the rest of HOFBrINCl • The formula is always the symbol of the element with a “2” beneath it. • E.G. If you were asked to get the formula for Chlorine Gas: • The formula would be Cl2