Unit 3: Atomic Structure Study Guide Name:
Date:
Atomic Notation
 State the location and charges of each subatomic particle within the atom
Per:
 Use the periodic table to determine the number of protons, neutrons, and electrons in an atom of an element
 Define atomic number as it relates to subatomic particles
 Define atomic mass as it relates to subatomic particles
 Draw a Bohr Model of an atom, given its atomic notation
 Identify the number of valence electrons from a diagram or Bohr Model
Isotopes and Relative Atomic Mass
 Define isotope
 Calculate the average atomic mass of an element, given the mass and abundance of naturally occurring isotopes
 Use isotope notation to determine the number of protons, neutrons, and electrons for an isotope of an element.
 Write an isotope symbol when given information about the number of subatomic particles in an isotope of an element
Nuclear Reactions
 Describe half-life as the amount of time it takes for half of a radioactive sample to decay
 Perform basic half-life calculations
 Write nuclear equations to show the key properties of alpha, beta, and gamma decay
 Recognize the energy outputs of fission and fusion reactions
Energy Levels and Electron Configuration
 State the energy sublevels (s, p) within an energy level
 State the maximum number of electrons that can occupy a given energy level and sublevel
 List the order of sublevels according to increasing energy
 Write the predicted electron configuration for the first 20 elements
 Identify the number of valence electrons from an electron configuration
Ions
 Describe the formation of ions as either a gain or loss of electrons
 Determine ion charge based on the number of valence electrons present in the neutral atom
 Predict the ion charge based on location on the periodic table
 Write isotope notation for ions
 Determine if an ion is a cation or anion
1.
Complete the following table.

2.
Consider the following: 𝑃𝑡 195
78 a.
What is the atomic number? b.
What is the atomic mass? c.
How many protons? d.
How many neutrons? e.
How many electrons?
3.
Consider the following: Chlorine-35. a.
Write the atomic/isotope notation. b.
Draw a Bohr model. c.
How many valence electrons?
4.
Define isotope.
5.
Silver has two isotopes, Silver-107 (52%) and Silver-109 (48%), calculate the average atomic mass for silver. SHOW YOUR WORK!
6.
How much of a 10.0g sample of a radioactive substance would remain after 4 half-lives?
7.
If 25g of a sample of radioactive substance is remaining after 1000 years, and the half-life of the substance is 250 years, how much of the substance was originally present?

8.
What is the symbol(s) for alpha decay?
9.
What is the symbol(s) for beta decay?
10.
Write the alpha decay reaction for Ruthenium-101.
11.
Write the beta decay reaction for Scandium-45.
12.
Define fission. How could you recognize if a fission reaction was illustrated?
13.
Define fusion. How could you recognize if a fusion reaction was illustrated?
14.
Write an electron configuration for a neutral atom of oxygen. a.
Identify the energy levels by circling them. b.
Identify the energy sublevels by underlining them. c.
Put a box around the electrons. d.
Highlight the valence electrons. e.
If oxygen forms an ion, will electrons be gained or lost? f.
What charge will an ion of oxygen have? g.
Write the isotope notation for the ion of oxygen. h.
Is an ion of oxygen a cation or anion? Explain your reasoning.
15.
Describe how ions form.