1. How Atoms Bond And Molecules Attract
Chapter 7
How Atoms Bond And Molecules Attract

2. Electron-Dot Structures
Atoms are held together by an electrical force known as the chemical bond.
Atoms bond using the outermost electrons known as valence electrons.

3. Electron-Dot Structures

4. Electron-Dot Structures

5. Atoms Can Lose or Gain Electrons to Become Ions
Any atom having a net electric charge is an ion.
A positively charged ion is called a cation.

6. Atoms Can Lose or Gain Electrons to Become Ions
A negatively charged ion is called an anion.

7. Atoms Can Lose or Gain Electrons to Become Ions

8. Ionic Bond Result from a Transfer of Electrons
Some atoms tend to lose electrons and others tend to gain them.
This electric force of attraction between two oppositely charged ions is called an ionic bond

9. Ionic Bond Result from a Transfer of Electrons

10. Ionic Bond Result from a Transfer of Electrons
For all ionic compounds, positive and negative charges must balance.
Ionic bonds result from a metal and a nonmetal

11. Ionic Bond Result from a Transfer of Electrons

12. Ionic Crystals
Crystal lattice is a 3-D geometric arrangement of particles.
Lattice energy is the energy required to separate the ions.

13. Metal Atoms Bond by Losing Their Electrons
Metals bond by losing their outer electrons.
This “fluid” of negatively charged electrons holds the positively charged metal ion together in a bond known as metallic bond.

14. Metal Atoms Bond by Losing Their Electrons
An alloy is two or more metals bonded to each other.

15. Properties of Metals Ductile- can be drawn into wire.
Malleable- can be hammered into thin sheets.
Metals are electrically conductive.

16. Metal Atoms Bond by Losing Their Electrons
Rocks that contain metal compounds are called ores.

17. Covalent Bonds Result from a sharing of Electrons
A covalent bond results from the sharing of electrons.
Compounds held together by covalent bonds are called molecules.

18. Covalent Bonds Result from a sharing of Electrons

19. Covalent Bonds Result from a sharing of Electrons

20. Electrons May Be Shared Unevenly in a Covalent Bond
Two atoms in a covalent bond may share the electrons equally or unequally.

21. Electrons May Be Shared Unevenly in a Covalent Bond
This separation of charge is called a dipole.

22. Electrons May Be Shared Unevenly in a Covalent Bond
When no dipole is formed the bond is classified as nonpolar.
When a dipole is formed the bond is classified as polar.

23. Electrons May Be Shared Unevenly in a Covalent Bond
Electronegativity is the ability of an atom to pull electrons toward itself.

24. Electrons Are Shared Unevenly in a Polar Molecule
Dipoles that are equal and pull in opposite directions cancel each other out.

25. Electrons Are Shared Unevenly in a Polar Molecule