1. Compounds

2. Compounds…24
Compounds
Examples of compounds
A pure substance made up of 2 or more elements chemically combined NaCl – salt H2O- water C6H12O6-sugar

3. Salt – Sodium- Chlorine- Water- Hydrogen Oxygen-
Compounds have different properties than the elements that make them up
Salt – Sodium- Chlorine- Water- Hydrogen Oxygen-
White, solid, edible
explosive
Toxic gas
Clear liquid
flammable gas
flammable gas

4. Chemical Formula Subscript-
a chemical symbol that represents the element and the number of atoms
a number written below and to the right of the symbol
H20
2 HYDROGENS
1 OXYGEN

5. Compounds Form using definite ratios of elements
H2O-water H2O2-peroxide CO- carbon monoxide (car exhaust) CO2-carbon dioxide

6. It’s Difficult Compounds can be broken down
Can only be broken down using a chemical change

7. Sodium

8. Compound Models … 25
Molecule-two or more atoms bonded together Compounds – two or more different types of atoms Covalent bond – sharing of a pair of electrons between two atoms. Occurs between two nonmetals Ionic bond – transfer of electrons to create ions. Occurs between a metal and a nonmetal