2. Water Molecule Atoms are made up of: Protons, Neutrons, Electrons Molecule: a combination of atoms which are bound together. Three important bond types: Ionic bonds: complete transfer of electrons (for example salts like NaCl) Covalent bonds: sharing of electrons (for example water H 2 O) Metallic bonds (for example Fe)

3. Water Molecule: Covalent Bonds In water, each hydrogen nucleus is bound to the central oxygen atom by a pair of electrons that are shared between them; chemists call this shared electron pair a covalent chemical bond.

4. Water Molecule: The Sharing is Not Equal! Each electron from hydrogen atoms is pulled slightly toward the positively charged protons in the nucleus of the oxygen atom, creating a slight positive charge on the exposed “hydrogen end” of the water molecule, and a slight negative charge on the “oxygen end” of the water molecule

5. Water Molecule: Water is special This property makes each water molecule like a tiny, weak magnet. Magnets have positive and negative “poles,” so water molecules are called “polar.”

6. Water Molecule: Water is special The fact that water molecules are polar gives rise to some interesting properties: The attractive forces between water molecules allows water to be a liquid rather than a gas at room temperature Water makes a great “solvent.”: Solvent: a solid, liquid or gas that dissolves another solid, liquid or gas, creating a solution. When materials, especially salts, are added to water the molecules are surrounded by water molecules and then easily dissolved Surface tension

7. Making a water molecule Follow the instruction on the water molecule worksheet Please return the information sheet to me.