atomic number = number of neutrons

Chapter 4 Review
1. What are the three parts of an atom and what are their charges?
Protons (+)
Neutrons (no charge)
Electrons (-)
2. What is an atom?
The smallest particle of matter or building block of a substance
3. What is an element?
A substance made of all the same type of atom
4. What does the atomic number tell us?
The number of protons
5. How do you determine the number of neutrons in an atom?
Atomic mass number – atomic number = number of neutrons
6. What is an isotope?
An atom of the same element with a different number of neutrons
7. What is an ionic bond?
 Chemical bond in which atoms transfer elections
 The atom that loses an election for a positive ion and the atom
that gains an election forms a negative ion; opposites attarct
8. What is a covalent bond?
Chemical bond in which atoms share pairs of elections
Directions: You may use your periodic table for the following questions.
1. For each element listed, identify the number of protons, neutrons, and electrons.
Aluminum (Al)
Tin (Sn)
2. For each element listed, draw the Bohr model.
Additionally, identify the oxidation number of the element.
List 2 examples of elements of that oxidation number with which it will bond to become stable.
If it is already stable and would not bond with another element, write “stable.”
Magnesium (Mg)
Helium (He)
Oxidation #___+2___
Oxidation #___0____
Bonds with ox. #__-2______
Bonds with ox. #_none______
Two examples:_____oxygen_________
______any from group 16__________
Two examples:________Already Stable__________
_________Noble Gas__________________
3. Happy or Unhappy? Fill in the chart below to determine if the compound is stable (happy) or
unstable (unhappy).
Chemical Formula Oxidation Numbers for
Each Element
Sum of Oxidation
Happy or Unhappy?
K +1
O -2
H +1
Al +3
O -2
O -2