1. Chapter 5-1 The Structure of Matter
Compounds and Molecules

2. What is a Compound? Compound – when 2 or more elements combine
New properties
NaCl (Table Salt)

5. Chemical Bonds
Chemical Bonds – attractive force that holds atoms or ions together

7. Compound A compound always has the same chemical formula
Sugar C12H22O11
Water H20
Salt NaCl

8. Chemical Structure
Chemical Structure – arrangement of atoms in a substance
How they are connected
Bond Length – average distance between nuclei of 2 bonded atoms

9. Chemical Structure
Bond Angle – angle formed by 2 bonds to the same atom
Boomerang shape instead of straight line

10. Models of Compounds 1. Ball and Stick Models
2. Structural Formulas – show structure of compound
3. Space Filling Models – shows space filled by each atom

11. Structure Different structures give compounds different properties
Compounds with network structures are strong solids
Quartz
Hard / High melting point

12. Structure Some compounds are made of networks of bonded ions NaCl
Na+ and Cl- ions

13. Structure Some compounds are made of molecules C12H22O11
Weaker attractions

14. Hydrogen Bonds
Hydrogen bonds – intermolecular attractions that occur between water molecules

15. Molecules and Compound What’s the difference?
Molecules – same or different elements
Compounds – different elements
All compounds are molecules 15