1. Chapter 4: Formation of Compounds
Section 4.1: The Variety of Compounds

2. Objectives: Distinguish the properties of compounds from those of the elements of which they are composed, Compare and contrast the properties of sodium chloride, water and carbon dioxide

3. What is an element. What is a compound. How do they differ
What is an element? What is a compound? How do they differ? ** Compound formation is only a rearrangement of valence electrons**

4. Physical/Chemical Properties of Salt:
Compound; Chemical Formula: NaCl 1. white solid at 200C 2. crystalline shape 3. brittle 4. melts at 8000C 5. dissolves easily in water 6. non-conductor when solid, but conducts when molten/liquid 7. nonreactive/stable compound

5. NaCl

7. Properties of Sodium Element; Symbol: Na
1. shiny, silvery-white, soft solid at room temp
2. melts at 980C
3. reacts with oxygen to form sodium oxide, Na2O
4. reacts with water to form hydrogen gas, and sodium hydroxide, NaOH (this is why its pure form is stored in oil)
5. never found free in the environment b/c of its high reactivity

8. Sodium

9. Properties of Chlorine
Element; Symbol: Cl2 (this is what’s called a diatomic element) 1.pale green, poisonous, room temp 2. odor 3. kills living cells, disinfects 4. boiling point is a mere –340C 5. among the most reactive elements

10. Chlorine

11. Reaction of Sodium and Chlorine

12. Physical/Chemical Properties of Carbon Dioxide:
Compound; Chemical Formula: CO2
1. colorless gas at room temp
2. slightly soluble in water
3. freezing point = -800C, DRY ICE
4. relatively stable; puts out fire
5. ingredient in photosynthesis
6. tasteless and odorless

13. Properties of Carbon Element; Symbol: C
1. fairly unreactive solid at room temp
2. at higher temps, will react with MANY elements
3. burns easily and is an excellent heat source
4. carbon compounds are the basis of all living things

14. Carbon

15. Properties of Oxygen Element; Symbol: O2
1. colorless, odorless, tasteless
2. supports combustion (it is not flammable by itself)
3. slightly soluble in water
4. very reactive
5. 21% of air you breathe
6. most abundant element in the Earth’s crust

16. Oxygen

17. Physical/Chemical Properties of Water
Compound; Chemical Formula: H2O
1. gas at 1000C
2. solid at 00C
3. non-conductor (when distilled or pure)
4. great solvent
5. stable
6. good medium for other reactions to occur in
7. other ingredient in photosynthesis

18. Water (H2O)

19. Properties of Hydrogen
1. Lightest most abundant element in the universe 2. Odorless, tasteless, colorless nonmetal gas 3. Reactive compound that occurs in a variety of compounds 4. Does not conduct electricity and only slightly soluble in water

20. Hydrogen