Atomic Structure, Periodic Trends, and Chemical Bonding Study Guide

Study Guide - Smart Notes

Tailored notes based on your materials, expanded with key definitions, examples, and context.

Q1. Fill in the chart with charge, mass, and location of protons, neutrons, and electrons.

Background

Topic: Atomic Structure

This question tests your understanding of the basic subatomic particles that make up atoms, including their properties and where they are found within the atom.

Key Terms and Concepts:

Proton: Positively charged particle found in the nucleus.
Neutron: Neutral particle (no charge) found in the nucleus.
Electron: Negatively charged particle found outside the nucleus in electron clouds or shells.

Step-by-Step Guidance

Recall the charge of each subatomic particle: proton (+1), neutron (0), electron (-1).
Remember the approximate relative mass of each: proton (1 amu), neutron (1 amu), electron (about 1/1836 amu).
Identify the location: protons and neutrons are in the nucleus; electrons are in the electron cloud surrounding the nucleus.

Try filling in the chart before checking the answer!

Q2. Determine the number of protons, neutrons, and electrons in neutral atoms and isotopes.

Background

Topic: Atomic Number, Mass Number, and Isotopes

This question checks your ability to use atomic number and mass number to find the number of each subatomic particle in an atom or isotope.

Key Terms and Formulas:

Atomic Number (Z): Number of protons in the nucleus.
Mass Number (A): Total number of protons and neutrons.
Number of Neutrons:
Neutral Atom: Number of electrons equals number of protons.

Step-by-Step Guidance

Identify the atomic number (Z) for the element; this gives the number of protons.
Find the mass number (A); subtract the atomic number to get the number of neutrons:
For a neutral atom, the number of electrons equals the number of protons.

Try working through an example before checking the answer!

Q3. Calculate the average atomic mass of an element given the mass and percent abundance of its isotopes.

Background

Topic: Isotopes and Atomic Mass

This question tests your ability to use isotope data to calculate the weighted average atomic mass of an element.

Key Formula:

Step-by-Step Guidance

Convert percent abundance to decimal (fractional abundance) by dividing by 100.
Multiply each isotope's mass by its fractional abundance.
Add the results for all isotopes to get the average atomic mass.

Try calculating with sample numbers before checking the answer!

Q4. Give the name or symbol for an element.

Background

Topic: Periodic Table and Element Symbols

This question checks your familiarity with the names and symbols of elements on the periodic table.

Key Concepts:

Each element has a unique one- or two-letter symbol (e.g., H for hydrogen, Na for sodium).
Element names and symbols are standardized internationally.

Step-by-Step Guidance

Locate the element on the periodic table.
Match the symbol to the correct name, or vice versa.

Test yourself by matching a few elements before checking the answer!

Q5. Identify or give an example of a metal, nonmetal, and semimetal (metalloid).

Background

Topic: Classification of Elements

This question tests your ability to classify elements based on their properties and position on the periodic table.

Key Concepts:

Metals: Usually found on the left and center of the periodic table; good conductors, malleable, shiny.
Nonmetals: Found on the right side; poor conductors, brittle, dull.
Semimetals (Metalloids): Elements with properties between metals and nonmetals; found along the staircase line (e.g., Si, B).

Step-by-Step Guidance

Recall the general location of metals, nonmetals, and metalloids on the periodic table.
Think of common examples for each category (e.g., Fe for metal, O for nonmetal, Si for metalloid).

Try classifying a few elements before checking the answer!

Q6. Describe the trend for atomic size/atomic radius, ionic radii, 1st ionization energy, and electron affinity.

Background

Topic: Periodic Trends

This question tests your understanding of how atomic and ionic sizes, ionization energy, and electron affinity change across periods and groups in the periodic table.

Key Concepts:

Atomic Radius: Increases down a group, decreases across a period.
Ionic Radius: Cations are smaller, anions are larger than their parent atoms.
1st Ionization Energy: Energy required to remove the first electron; increases across a period, decreases down a group.
Electron Affinity: Tendency to gain electrons; generally becomes more negative across a period.

Step-by-Step Guidance

Recall the general trends for each property as you move across a period (left to right) and down a group (top to bottom).
Think about the underlying reasons (e.g., increasing nuclear charge, electron shielding).

Try explaining each trend in your own words before checking the answer!

Q7. Identify the element in each set with the largest or smallest value for atomic size, ionic radii, 1st ionization energy, and electron affinity.

Background

Topic: Periodic Trends Comparison

This question tests your ability to apply periodic trends to compare elements and predict which has the largest or smallest value for a given property.

Key Concepts:

Use the trends from Q6 to compare elements in the same group or period.

Step-by-Step Guidance

Locate the elements in question on the periodic table.
Apply the relevant trend (e.g., atomic radius increases down a group).
Determine which element should have the largest or smallest value based on its position.

Try comparing a set of elements before checking the answer!

Q8. Write the long-hand and abbreviated electron configurations for atoms and ions (up to 36 electrons).

Background

Topic: Electron Configuration

This question tests your ability to write electron configurations using the Aufbau principle, Pauli exclusion principle, and Hund's rule.

Key Concepts:

Long-hand: List all occupied orbitals in order (e.g., 1s2 2s2 2p6 ...).
Abbreviated: Use the previous noble gas in brackets, then continue (e.g., [Ne] 3s2 3p4).
For ions, add or remove electrons as needed.

Step-by-Step Guidance

Determine the number of electrons in the atom or ion.
Fill orbitals in order of increasing energy (1s, 2s, 2p, 3s, 3p, 4s, 3d, etc.).
For abbreviated, find the noble gas that precedes the element and use its symbol in brackets.

Try writing configurations for a few elements before checking the answer!

Q9. Name or give the symbol for elements.

Background

Topic: Periodic Table Familiarity

This question checks your ability to recall element names and symbols.

Key Concepts:

Practice matching names and symbols for common elements.

Step-by-Step Guidance

Review the periodic table and memorize common element names and symbols.
Test yourself by covering one column and recalling the other.

Try matching a few before checking the answer!

Q10. Give the name for groups 1, 2, 17 (7), and 18 (8) on the periodic table and identify representative elements.

Background

Topic: Periodic Table Groups

This question tests your knowledge of group names and the concept of representative elements.

Key Concepts:

Group 1: Alkali metals
Group 2: Alkaline earth metals
Group 17 (7): Halogens
Group 18 (8): Noble gases
Representative elements: Groups 1, 2, and 13–18

Step-by-Step Guidance

Locate each group on the periodic table.
Recall the group name and list a few elements from each group.

Try naming the groups and elements before checking the answer!

Q11. Write long-hand and abbreviated electron configurations for atoms.

Background

Topic: Electron Configuration

This question is similar to Q8 but focuses on neutral atoms.

Key Concepts:

Follow the same steps as in Q8 for neutral atoms.

Step-by-Step Guidance

Count the number of electrons for the atom.
Fill orbitals in order, using the periodic table as a guide.
Use noble gas abbreviation for the abbreviated form.

Try writing a configuration before checking the answer!

Q12. Know valence electrons and be able to give the number of valence electrons of a given element.

Background

Topic: Valence Electrons

This question tests your ability to determine the number of valence electrons, which are important for chemical bonding.

Key Concepts:

Valence electrons are the electrons in the outermost shell.
For main group elements, the group number often indicates the number of valence electrons.

Step-by-Step Guidance

Locate the element's group on the periodic table.
For groups 1, 2, and 13–18, the group number (or last digit) gives the number of valence electrons.

Try determining valence electrons for a few elements before checking the answer!

Q13. Know periodic trends for valence electrons, atomic size, and first ionization energy.

Background

Topic: Periodic Trends

This question checks your understanding of how these properties change across the periodic table.

Key Concepts:

Valence electrons increase across a period.
Atomic size decreases across a period, increases down a group.
First ionization energy increases across a period, decreases down a group.

Step-by-Step Guidance

Review the trends for each property as you move across periods and down groups.
Think about the reasons for these trends (e.g., effective nuclear charge, shielding).

Try explaining these trends before checking the answer!

Q14. Name and give formulas for ions, ionic compounds, and covalent compounds, including polyatomic ions (know the charges of polyatomic ions).

Background

Topic: Chemical Nomenclature

This question tests your ability to name and write formulas for different types of compounds and ions.

Key Concepts:

Ions: Atoms or groups with a charge (e.g., Na+, SO42−).
Ionic compounds: Made of cations and anions (e.g., NaCl).
Covalent compounds: Made of nonmetals sharing electrons (e.g., CO2).
Polyatomic ions: Charged groups of atoms (e.g., NO3−).

Step-by-Step Guidance

Identify the type of compound (ionic or covalent).
Recall naming rules for each type (e.g., -ide for binary ionic, prefixes for covalent).
For polyatomic ions, memorize common names and charges.

Try naming and writing formulas for a few compounds before checking the answer!

Q15. Draw electron-dot structures for covalent and ionic compounds.

Background

Topic: Lewis Structures

This question tests your ability to represent valence electrons and bonding in molecules and compounds.

Key Concepts:

Electron-dot (Lewis) structures show valence electrons as dots around symbols.
For covalent compounds, show shared pairs as lines or pairs of dots.
For ionic compounds, show transfer of electrons and resulting charges.

Step-by-Step Guidance

Count total valence electrons for all atoms in the molecule or ion.
Arrange atoms and connect with single bonds (pairs of electrons).
Distribute remaining electrons to satisfy the octet rule (or duet for H).

Try drawing a structure before checking the answer!

Q16. Determine geometrical shapes of molecules from electron dot structures (angular, tetrahedral, trigonal planar, etc.).

Background

Topic: Molecular Geometry (VSEPR Theory)

This question tests your ability to predict molecular shapes based on electron pair arrangements.

Key Concepts:

VSEPR theory: Electron pairs repel and arrange as far apart as possible.
Common shapes: linear, bent (angular), trigonal planar, tetrahedral, trigonal pyramidal, etc.

Step-by-Step Guidance

Draw the Lewis structure for the molecule.
Count the number of bonding pairs and lone pairs around the central atom.
Use VSEPR theory to determine the molecular geometry.

Try predicting the shape for a molecule before checking the answer!

Q17. Determine if molecules are polar, non-polar, or ionic.

Background

Topic: Molecular Polarity

This question tests your ability to determine the type of bonding and whether a molecule has a dipole moment.

Key Concepts:

Polarity depends on difference in electronegativity and molecular geometry.
Ionic compounds have large differences in electronegativity; covalent can be polar or non-polar.

Step-by-Step Guidance

Determine the type of bond (ionic or covalent) based on elements involved.
For covalent molecules, check if the molecule is symmetrical and if bond dipoles cancel.

Try classifying a molecule before checking the answer!

Q18. Identify attractive forces in compounds (interatomic, intermolecular forces, etc.) and their relative strengths.

Background

Topic: Chemical Bonding and Intermolecular Forces

This question tests your understanding of the different types of forces that hold atoms and molecules together.

Key Concepts:

Interatomic forces: Ionic, covalent, metallic bonds (strongest).
Intermolecular forces: Hydrogen bonding, dipole-dipole, London dispersion (weaker than interatomic).
Relative strengths: Ionic > covalent > hydrogen bond > dipole-dipole > dispersion.

Step-by-Step Guidance

Identify the types of particles or molecules involved.
Determine which forces are present based on structure and composition.
Rank the forces by their relative strengths.