Matter and Measurement
Density
Core Concepts In this tutorial, you will learn what density is, and how to calculate it. You will also learn the units and you will find out if it is a physical property. Topics Covered in Other Articles What is
What is Matter?
Core Concepts In this tutorial, you will learn about matter, its properties, an introduction about its history, the difference between matter and mass. Topics Covered in Other Articles Defining Matter In science there are many different definitions of matter. Usually
Physical vs Chemical Properties
Core Concepts In this tutorial on physical versus chemical properties, you will learn about the differences between physical, chemical, intensive and extensive properties. We will also cover physical versus chemical changes. Topics Covered in Other Articles Physical vs Chemical Properties
What is UV-Vis Spectrophotometry?
Core Concepts In this article, you will explore the components of UV-Vis spectrophotometry, its discovery, how it works, and some applications. What is UV-Vis spectrophotometry? UV-Vis spectrophotometry is an analytical technique that measures the wavelengths of light, from the ultraviolet
Moles and Avogadro’s Number
Core Concepts So what is a mole? In this tutorial, you will learn the definition of the mole, an important unit of measurement in chemistry. You will also learn about Avogadro’s number and why it is useful. From here, you
What are Significant Figures?
Core Concepts In this tutorial about significant figures, we will cover their definition, relevant guidelines, and historical context. Topics Covered in Other Articles What are Significant Figures? Significant Figures, often referred to as “Sig Figs,” are specific digits that denote
Atoms and Molecules
Why Water Works
Core Concepts In this article, we will discuss the chemical structure, chemical properties, and key applications of water, one of the world’s most important molecules. Introduction Water is an inorganic compound made up of oxygen and hydrogen that is critical
What is Atomic Mass?
Core Concepts In this article you will learn about the different things that contribute to atomic mass. What makes up an atom, and how to determine atomic masses. Topics covered in other articles Introduction to Atomic Mass Number Atoms of
What is Atomic Number?
Core Concepts In this article, you will learn about atomic number, its definition, its usefulness in categorizing elements, and its history as a theory in chemistry. Topics Covered in Other Articles The Elements What exactly makes one element different from
What is an ion?
Core Concepts In this tutorial, learn what an ion is, and why it is important in chemistry. Topics Covered in Other Articles What is an ion? An ion is an atom or molecule with either a positive or negative electrical
Rutherford Atomic Model
Learn about the Rutherford atomic model, the gold foil (scattering) experiment, and the limitations of Rutherford’s model!
Chemistry Prefixes
Core Concepts In this tutorial, you will be introduced to the different types of chemistry prefixes. You will also learn the basics of these chemistry prefixes and how they are applicable in the real world today! Lastly, you will be
Chemical Reactions and Stoichiometry
Calculating Percent Yield
Core Concepts In this tutorial, you will learn calculating percent yield and theoretical yield are, and how to calculate it. In addition, you will walk through an example calculation. Topics Covered in Other Articles What is Percent Yield? When performing
Law of Conservation of Matter
The Law of Conservation of Matter says that mass can not be created or destroyed. Below we go into detail on this law, work through some example questions, and discuss the origins of the Law of Conservation of Matter. What
Limiting Reactants and Limiting Reagents
Core Concepts In this tutorial, you will learn what a limiting reagent is, how to find the limiting reactant, and see some example problems. What is a Limiting Reagent? The limiting reactant is the reagent (compound or element) to be
Solving Stoichiometry Problems
Core Concepts In this tutorial, you will learn what is stoichiometry and the different types of problems involving it. You will go through several examples to practice and master the content! Topics Covered in Other Articles Stoichiometry Definition What is
Balancing Chemical Formula
Core Concepts In this article you’ll learn how to balance a chemical formula and how to determine an element’s charge from balancing. You’ll learn some key rules to remember and have access to a table with charges of polyatomic ions!
Types of Chemical Reactions
Types of Chemical Reactions: Core Concepts This article will cover the main classifications of chemical reactions: synthesis reaction, decomposition reaction, single replacement reaction (single displacement reaction), and double replacement reaction (double displacement reaction). We also discuss what is a combustion
Solutions and Solubility
Aqueous Solutions
Core Concepts Aqueous solutions are one of the most important types of mixture inside and outside the lab. Check out this article to learn more about the characteristics and properties of aqueous solutions! Topics Covered in Other Articles What are
Mixtures vs. Compounds
Find out what is a mixture, what is a compound, and the difference between heterogeneous and homogeneous mixtures in this tutorial. What is a Mixture? A mixture refers to a physical combination of two or more substances, where no reaction occurs. Because only a
Homogeneous and Heterogeneous Mixtures
In this article, we will discuss the definition of homogeneous and heterogeneous mixtures, and then look at some examples of each! It is very important to understand the differences, since they can influence many aspects of materials and processes. Heterogeneity
What is Solubility?
Core Concepts In this tutorial, you will be introduced to the properties of solubility and the varying factors that affect it. You will also be introduced to solutes, solvent, and solutions. Topics Covered in Other Articles Vocabulary Understanding Solutions To
What is Molality? Definition and Formula
Core Concepts In this tutorial on molality, you will learn the definition, importance, and how to calculate molality in understanding the concentration of a solution. Example calculations are provided. Topics Covered in Other Articles Vocabulary Solution Basics Solutions are mixtures
Solubility Rules & Chart
Solubility is one of most interesting parts of chemistry. Watching a colorful precipitate form, or redissolve, can be very exciting. In this article, we look at the common solubility rules of chemistry, which state which anions and cations are usually
Electronic Structure of Atoms
Hund’s Rule
What is Hund’s Rule? Hund’s Rule of Maximum Multiplicity, most commonly referred to as Hund’s Rule, states that every atomic orbital within a sublevel is singly occupied before it is doubly occupied and that all singly occupied orbitals possess electrons
Atomic Spectra
Core Concepts In this tutorial, you will learn about atomic spectra, including the meaning behind this term, why spectra appear the way they do, and applications of this unique phenomena. Topics Covered in Other Articles What is an Atomic Spectra?
How to Write Electron Configurations
Core Concepts In this tutorial, you will learn how to find and write the electron configurations and orbital diagrams for various elements using the periodic table. You will learn Aufbau’s principle, Hund’s rule and the Pauli exclusion principle. Related Articles
Electron Orbitals & Orbital Shapes
What is an Electron Orbital? Electron orbitals are mathematical functions that describe the probability of finding an electron around the nucleus of an atom. Each orbital can hold two electrons. They are also known as atomic orbitals. Atomic orbitals come
Electron Shells
Core Concepts In this tutorial, you will learn about electron shells, the different subshells that exist, and the orbitals where electrons can be found. Topics Covered in Other Articles The Bohr Model Niels Bohr developed an early model of the
What are Valence Electrons?
Core Concepts In this tutorial, we learn about valence electrons, what they are, and why they are significant. We will also learn how to tell how many valence electrons an element has. Topics Covered in Other Articles What are valence
Periodicity and the Periodic Table
What is Electronegativity? Trends & Chart
What is electronegativity? Electronegativity is defined as an atom’s ability to attract electrons towards it in a chemical bond. There are several different ways of measuring it, the most common being the Pauling scale. Different elements have different electronegativities based
Ionization Energy
What is Ionization Energy? Ionization energy, also called ionization potential, is a property that all elements on the periodic table have. So what is the definition of ionization energy? It is the amount of energy required to remove an electron
Periodic Table With Charges
Introduction: The layout of the periodic table and where an element is located, can tell you a lot about its properties! In this article, you’ll learn how you can figure out what an element’s charge is by looking at where
Ionic Radius Trends
Core Concepts In this tutorial, you will be introduced to ionic radius trends on the periodic table of elements. You will also be introduced to the concepts that contribute to ionic radius, including how to find it. Topics Covered in
Periodic Table Metals and Non-Metals
Core Concepts In this tutorial, you will be introduced to metals and non-metals on the periodic table of elements and their properties. Topics Covered in Other Articles Metals A majority of the elements on the periodic table of elements categorize
Atomic Radius Trend
What is the Atomic Radius? Let’s discuss the definition of the atomic radius, also called atomic size, and the atomic radius trend on the periodic table. The atomic radius is measured as half the distance between two nuclei of the
Chemical Bonding
Polar vs. Non-Polar Bonds & Molecules
In this chemistry tutorial, we explain the difference between polar bonds and non-polar bonds. We then tell you the definition of a polar molecule, and what a non-polar molecule is. Last, but not least, you learn what a dipole moment
Bond Formation and Dissociation Energies
What is Bond Energy? No molecule within chemistry would exist without bonds linking atoms. Because forming bonds releases energy, molecules exist because atoms prefer a stable compound with less energy. In order to break these stable bonds, energy must be
Sigma Bonds and Pi Bonds
Core Concepts In this article, you will learn about the basics of sigma and pi bonds and their significance in organic chemistry. You’ll also have the opportunity to apply what you know through some examples. Topics Covered in Other Articles
Orbital Diagrams
What are Orbital Diagrams? Electron orbital diagrams are diagrams used to show the energy of electrons within the sublevels of an atom or atoms when used in bonding. Single atom diagrams (atomic orbital diagrams) consist of horizontal lines or boxes
Bond Enthalpy & Bond Energy
Core Concepts In this tutorial, you will learn about bond energy, bond enthalpy, and its relationship to bond order and enthalpy. You will also learn about the formation and breakdown of a bond, along with exothermic and endothermic reactions. Topics
What is a Polar Covalent Bond?
Core Concepts In this tutorial, we will be discussing what makes a bond polar, how a polar covalent bond is defined, examples of polar covalent bonds, and finally, steps to solve a polarity question. Topics Covered in Other Articles What
Molecular Structure
Geometric Isomerism
In this tutorial, you will learn about isomers, geometric isomerism in alkenes and cycloalkanes, and cis-trans versus E-Z notation.
Lewis Dot Structures
Core Concepts In this tutorial, you will learn how to draw the correct lewis dot structures for elements and compounds. In addition, you will learn about valence electrons and the octet rule. Topics Covered in other Articles Polyatomic Ions Electrons
VSEPR Theory & Chart
What is VSEPR Theory? VSEPR Theory is short for Valence Shell Electron Pair Repulsion Theory, a method of organizing molecules based on their geometric structures. In chemistry, VSEPR Theory is based on the principle that each atom in a molecule
Bond Order vs. Bond Length
Core Concepts – Bond Length In this tutorial, you will learn about the definition of a chemical bond, and the key differences between bond order and bond length. You will also learn about how these characteristics relate to each other,
Coordination Number in Chemistry
Core Concepts In this article, you will learn about coordination number in chemistry, including its meaning in molecules, metal ion complexes, and crystals. You will also explore the implications of coordination numbers in molecular geometry. Topics Covered in Other Articles
Complex Ions and Ligands in Chemistry
Core Concepts In this article, you will learn about complex ions in chemistry and their ligands. We’ll cover the various types of complexes, the importance of coordination number, and the chemistry of ligands, including ligand substitution reactions. Topics Covered in
Acids and Bases
What is Kw in Chemistry?
Core Concepts – Kw Equilibrium In this article, you will learn about the concept of Kw in chemistry. Kw combines conceptual knowledge from branches like equilibrium, acids/bases, and properties of water to form a useful tool. Topics Covered in Other
Acid Base Chemistry
Introduction to Acid Base Chemistry Acids and bases are essential for many processes such as: maintaining homeostasis in the body, sustaining plant growth, and preserving aquatic life. They are also used in products found in the home. Acids and bases
Monoprotic, Triprotic, and Polyprotic acids
Core Concepts In this tutorial, you’ll learn the definitions of monoprotic, diprotic, triprotic, and polyprotic acids. You will also learn about the trends of acidity between different acids, between protons within polyprotic acids, and polyprotic acid titration curves. Topics Covered
Titration Curves & Equivalence Point Calculations
Amazing facts about titration analysis, including the types, components, curves, and steps of titrations
What is pH? The pH Formula & Equation
pH is a measure of how acidic or basic a substance is. In our everyday routine, we encounter and drink many liquids with different pH. Water is a neutral substance. Soda and coffee are often acidic. The pH is an
Buffer Capacity & Calculations
Read this tutorial to learn what buffer capacity is, and how to calculate it!
Redox Reactions
What is Electrochemistry?
Core Concepts In this tutorial, you’ll learn the basics of electrochemistry, including oxidation, reduction, galvanic cells, and applications of electrochemistry. We’ll also go over the fundamental electrochemistry equations and how to use them. Electrochemistry is the field that studies the
Redox Reactions & Oxidation Reduction
Core Concepts In this tutorial, you will learn what a redox reaction is, the different parts of such a reaction, as well as how to recognize and write redox reactions. You will also learn the difference between oxidation and reduction,
Standard Reduction Potentials made easy
Standard reduction potentials are very useful in chemistry. They are also known as standard cell potentials, or standard electrode potentials. They are measured in volts, and they tell you how likely an element or ion is to be reduced by
How to Balance Redox Reactions
Core Concepts Redox reactions are incredibly interesting and important reactions in chemistry, particularly in electrochemistry! However, they are not of much use unless properly balanced. In this tutorial, you will learn how to balance redox reactions, and what it means
Lithium-Ion Batteries
Core Concepts In this article, you will explore the lithium-ion battery, its compartments, and redox reactions that occur within it. You will also gain an overview of its work functions, applications, and advantages and disadvantages. Introduction A lithium-ion battery (LIB)
How to Find Oxidation Number & Oxidation State
Oxidation number and oxidation state are two very important concepts in chemistry. In this article, we will make them very easy to understand! Topics Covered in Other Articles: Cations and IonsRedox ReactionsCommon polyatomic IonsElectrochemical cellsWhat are ions? Oxidation Number –
Gases
Understanding Kinetic Molecular Theory
Core Concepts You will learn the kinetic molecular theory of gases, and how to use the root-mean-square formula to determine the average speed of gas. Covered in Other Articles What is the Kinetic Molecular Theory? Kinetic molecular theory is a
What is Partial Pressure?
Core Concepts In this article, we learn about partial pressure and its importance with respect to Dalton’s Law, the Ideal Gas Law, mole fractions, and L’Chatelier’s Principle. Topics Covered in Other Articles Pressure and Partial Pressure Physical chemists tend to
Raoult’s Law Equation
Raoult’s law is used to determine the vapor pressure of ideal solutions with nonvolatile solutes based on the vapor pressure of the solvent and the mole fraction of the solvent. Below we discuss what the equation of Raoult’s law is,
Brownian Motion
What is Brownian Motion? Brownian motion is the random movement of particles in a liquid or gas. This movement occurs even if no external forces applied. Particles are never staying completely still. Instead, the movement occurs because of particles colliding
Combined Gas Law
Core Concepts The combined gas law defines the relationship between pressure, temperature, and volume. It is derived from three other names gas laws, including Charles’ law, Boyle’s law, and Gay-Lussac’s law. Below we explain the equation for the law, how
Boyle’s Law
Boyle’s Law Core Concepts In this tutorial, you will learn about the Boyle’s law formula, and how this equation can be used to determine relationships between changes in pressure and changes in volume in a given closed system. Robert Boyle,
Liquids and Solids
Thermochemistry Vocabulary
Core Concepts – Thermochemistry Vocabulary In this article you’ll learn the definitions and gain a better understanding of the main vocabulary terms for thermochemistry such as the different kinds of systems and what it means to have surroundings. The terms
Standard State
Core Concepts In this article you will be able to understand the standard state of every element. After reading this article you’ll know the exact values of different standard sates, and its importance to chemistry. Related Topics Standard State In
State Variables vs. Path Variables
Core Concepts In this article, you will learn how to distinguish between state variables and path variables/functions, describe each type, and convert between them. Topics Covered in Other Articles Thermodynamic Variables: State Variables vs. Path Variables In chemistry, we use
What is Thermochemistry?
Core Concepts In this article, you will learn about the central concepts in thermochemistry, and how thermochemical laws guide the study of heat’s interactions with the world. You will also learn some crucial formulas and how to solve thermochemistry problems.
What is Gibbs Free Energy?
Core Concepts Gibbs free energy is an important value in thermodynamics that allows you to predict aspects of a chemical reaction. In this tutorial, we will learn why the Gibbs free energy equation is important and how to solve problems
The Laws of Thermodynamics
Core Concepts There are three fundamental laws of thermodynamics, which deal with the movement and transfer of energy. Let’s learn about them in this tutorial. We will discuss the first law of thermodynamics, the second law of thermodynamics, and the
Equilibrium
What is the Equilibrium Constant?
Core Concepts In this article about chemical equilibrium, we will learn about the equilibrium constant, also often referred to as the equilibrium coefficient. This article explains what the equilibrium constant is, why it is significant, and how to calculate it.
What is Le Chatelier’s Principle?
Core Concepts Le Chatelier’s principle is one of the most important concepts with regard to chemical equilibrium. It allows us to predict the behavior of a system in equilibrium under various conditions. In this tutorial, we will cover the definition
Using an ICE Table
Core Concepts In this tutorial, we will learn about the ICE table for chemistry: a method of completing calculations in equilibrium reactions, either to find the concentrations of reactants and products, or to find the value of the equilibrium constant.
Solubility Product Constant (KSP)
What is Ksp? , or the solubility product constant, is a unitless measure of how well a solid dissolves in an aqueous solution. To be precise, is an equilibrium constant, which tells how much a solid dissociates when the dissolution
Equilibrium Conditions
Core Concepts In this article, you’ll learn the conditions for a chemical system at equilibrium, equilibrium constant concentrations, and their applications in kinetics. Topics Covered in Other Articles What is Chemical Equilibrium? Chemical equilibrium refers to a condition where the
Reaction Kinetics
Reaction Rates & How to Determine Rate Law
Core Concepts Some reactions will go fast, and some will go slow – the speed of the reaction is its reaction rate, which is dictated by a rate law. In this article, we will learn about reaction rates, rate laws,
Catalysts & Activation Energy
What is a catalyst? Let’s talk about what catalysts are. A catalyst is a compound or element that increases the rate of a chemical reaction, e.g. the speed at which it occurs, without itself being part of the reaction. Generally
Integrated Rate Laws
Core Concepts In this article, you will learn about integrated rate laws, including their chemical meaning, mathematical derivation, and usefulness in studying chemical kinetics. Topics Covered in Other Articles Rate Laws and Integrated Rate Laws Chemical reactions can happen at
Rate-Determining Step
What is a rate-determining step? The rate-determining step in a reaction is the step which will take the longest time in a reaction. It is the slowest part of the reaction mechanism and will determine how fast the overall reaction
Arrhenius Equation
Core Concepts In this tutorial, you will learn what the Arrhenius equation is, how to use the equation to determine the activation energy or rate constant of a reaction, and how to derive it. Using the Arrhenius Equation is an
Nuclear Chemistry
Radioactive Decay
Core Concepts In this article you will be able to understand what is radioactive decay and its different processes. After reading this article you will differentiate alpha, beta, gamma and other forms of radioactive decay. Related Topics Radioactive Decay An
Alpha, Beta, and Gamma Particles
Core Concepts In this article, you will explore the properties of radioactive alpha particles, beta particles, and gamma rays, as well as how to stop them. Topics Covered in Other Articles What is radiation? Nuclear scientists use the term radiation
Nuclear Reactions
Core Concepts In this tutorial, you will learn all about nuclear reactions. This includes an introduction to nuclear reactions and a discussion about how to write their equations. We also consider the different types of nuclear reactions, which include nuclear
How to Find Number of Protons, Neutrons, and Electrons
Core Concepts In this tutorial, you will learn how to find and calculate the number of protons, neutrons, and electrons in an atom or element. In addition, you will learn about the different subatomic particles. If you enjoy this tutorial,
What is an Isotope?
What is an isotope? An isotope is an atom that has the same number of protons and a different number of neutrons. The atom is still considered the same element (still contains the same number of protons) as before but
Fundamental Particles and Particle Physics
Core Concepts In this article, you will learn what fundamental particles are, how they were discovered, and where the next frontiers of this field of science are. The Fundamentals of the Fundamentals What makes a particle fundamental or elementary? Fundamental
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Hess’s Law
Core Concepts In this tutorial, you will be introduced to Hess’s Law, as well as the equation that goes along with this concept. In addition, you will further master this concept by going through some example problems. Topics Covered in
Sigma Bonds and Pi Bonds
Core Concepts In this article, you will learn about the basics of sigma and pi bonds and their significance in organic chemistry. You’ll also have the opportunity to apply what you know through some examples. Topics Covered in Other Articles
Common Ion Effect
Core Concepts In this tutorial, you will be introduced to the common ion effect. You will learn what it is, how it works and about its overall effect on solubility and precipitates in both chemical reactions and the real world.
Dimensional Analysis
Core Concepts In this tutorial, you will learn what dimensional analysis is in the field of chemistry, how to use it, see examples, and learn how it can be applied to chemistry. Topics Covered in Other Articles What is Dimensional
Radioactive Decay
Core Concepts In this article you will be able to understand what is radioactive decay and its different processes. After reading this article you will differentiate alpha, beta, gamma and other forms of radioactive decay. Related Topics Radioactive Decay An
What is an Isotope?
What is an isotope? An isotope is an atom that has the same number of protons and a different number of neutrons. The atom is still considered the same element (still contains the same number of protons) as before but