1. Chemical Bonding 176

2. 1. What are valence electrons?
Are the electrons that are in the outermost energy level and are held most loosely.

3. 2. How is the reactivity of elements related to valence electrons?
The number of valence electrons in an atom of an element determines the ways in which the atom will bond with other atoms.

4. 3. How can you use the periodic table to predict valence electrons?
Generally, the valence electrons are the same as the group number

6. 4. What makes atoms unstable?
Incompletely filled valence electron shells.
Atoms are stable when they have 0 or 8 electrons in outer level.
They will gain, lose, or share electrons to empty or fill outer level.

7. 5. What is chemical bonding?
The joining of atoms to form new substances.

8. 6. Why do atoms bond?
To become more stable

9. 7. What is a chemical bond?
The force of attraction that holds two atoms together.

10. Example:
Sodium (Na) +
(Explosive metal!)

11. Chlorine (Cl)
(toxic gas!)

24. = NaCl (table salt)

25. 8. What are 3 ways that atoms can form bonds?
Ionic bonds
Covalent bonds
Metallic bonds

26. 9. How does an ionic bond form?
When valence electrons from one atom are transferred to another atom.
They become charged ions
Positive and negative charged ions are attracted to each other.

30. What do you call a chemical bond that is sarcastic?
An ironic bond.

32. 10. What is a compound?
A substance made up of two or more different elements.
The properties of the compound are different from the elements by themselves.

33. 11. What is a chemical formula?
A shorthand way to use chemical symbols and numbers to represent a substance.
Ex: H2O H = hydrogen
O = oxygen

37. 12. What is a covalent bond?
A bond formed when two atoms share electrons.

41. 13. What is a molecule?
A neutral group of atoms joined together by a covalent bond.
The properties of the molecule are different from the atoms by themselves.

44. Glucose

46. Caffeine

47. Alcohol (ethanol)

48. Nicotine

49. 14. What is a metallic bond?
A bond in which valence electrons are free to move from atom to atom.
“sea of electrons”