1. STATES OF MATTER And IMF’s

2. STATES OF MATTER What is different about each? Record in your notes and discuss with a neighbor.

3. IMF AND STATES The state of a substance depends largely on the balance between the kinetic energies of the particles (atoms, molecules or ions) and the interparticle forces of attraction. As the strength of intermolecular forces increase the particles are held together stronger. As kinetic energy increases (temperature) particles move apart. Gases at room temperature have weak IMFs compared to liquids. As IMF’s increase in strength, the boiling points and melting points of chemicals increase. Meaning it takes more energy to boil/melt them.

4. Cl 2 Br 2 I 2 In nonpolar molecules with only London dispersion forces, the more electrons the substance has the stronger the IMF.

5. LEARNING CHECK Which of the following would have the lowest boiling point? A.Argon (Ar) B.Krypton (Kr) C.Helium (He) D.Neon (Ne)

6. COMPARING SIMPLE CARBON COMPOUNDS CH 4 (methane) is the simplest carbon compound. As carbons are added and the chain lengthens the compounds have more electrons and therefore the London dispersion forces grow stronger. CH 4 – C 4 H 10 are all gases at room temperature (about 25  C) (propane, butane etc) C 5 H 12 – C 10 H 22 are all liquids (hexane, octane etc) C 11 H 24 and above are solids (things like waxes and tar)