Matter and Measurement
What Is Matter?
Core Concept 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
Density – Definition and How to Calculate It
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
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
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
What is a Mole and Avogadro’s Number in Chemistry
Core Concepts – Mole in Chemistry 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
States of Matter
Core Concept – States of Matter In this tutorial, you will learn about the four main states of matter (solid, liquid, gas, and plasma), as well as some intermediate states of matter, by reading about their properties, applications, and examples.
Atoms and Molecules
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 Cations and Anions Electrochemistry Bond Enthalpy and Entropy Ionization Energy Electron Affinity Ion Definition An ion is an
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
What Is An Element in Chemistry?
Chemical elements. Atomic elements. Simple substances. Elements of the periodic table. These are all different terms for the same concept. A long time ago, “elements” used to mean earth, air, wind and fire – but that is no longer true.
Chemical Reactions and Stoichiometry
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
What is a Chemical Reaction? Physical vs Chemical Change Examples
How is a Chemical Reaction Defined? What is a chemical reaction? What is a chemical change, and what is a physical change? A chemical reaction occurs when compounds or substances undergo a chemical change to form different compounds or substances.
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 mass. What
Limiting Reactant and Limiting Reagent
Core Concepts – Limiting Reactant: 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
What is a Reactant in Chemistry?
Core Concepts In this tutorial, you will learn what a reactant is and where to find a one in a chemical equation. You will also learn the difference between a reactant and a reagent, and be introduced to many examples
Decomposition Reaction in Chemistry
In this tutorial, you will learn what a decomposition reaction is and its types. You will also get to explore some of its fascinating examples!
Solutions and Solubility
¿Qué es una solución en química?
Una solución es mucho más que la respuesta a un complicado problema matemático. También es un término químico. Aprende qué son las soluciones, cómo identificarlas y ejemplos de soluciones comunes. ¿Qué son las soluciones? Una solución es lo que ocurre
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
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
How to Calculate Molarity & Molarity Formula
Core Concepts In this tutorial, you will learn the molarity formula, and how to calculate the molarity of a solution using the molarity equation. If you enjoy this article, make sure to check out other resources linked below! Topics Covered
What is a Solution in Chemistry?
A solution is much more than an answer to a complicated math problem. It is also a chemistry term! Learn what solutions are, how to identify them, and examples of common solutions! What are Solutions? A solution is what occurs
Electronic Structure of Atoms
Pauli Exclusion Principle
Pauli Exclusion Principle Definition The Pauli Exclusion Principle states that in any atom no electron can have the same four electronic quantum numbers as another electron. Every electron must have different quantum numbers. So, in each electronic orbital (same n,
Aufbau Principle
What is the Aufbau Principle? The Aufbau principle states that electrons will first fill the lowest energy electron shells in a neutral atom. Electrons fill orbitals from lowest energy orbitals to highest energy orbitals. The Aufbau principle helps to determine
Bohr Model of the Atom
Bohr Model – Core Concepts: In this tutorial, you will learn what the Bohr Model is, how it improved upon previous models of the atom, and what problems the Bohr model fails to solve. What is the Bohr Model? The
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?
Electron Shells
Core Concepts In this tutorial, you will learn about electron shells, the different subshells, and the orbitals where electrons can be found. Topics Covered in Other Articles The Bohr Model Niels Bohr developed an early model of the atom in
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
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
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 Trends Made Easy!
What are Periodic Trends? Periodic trends are observable patterns in the properties of an element that are dependent on its position in the Periodic Table. These trends have allowed scientists in the past to predict certain characteristics of unknown elements.
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
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
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
Chemical Bonding
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
Molecular Orbital Theory
Core Concepts In this article, we learn about Molecular Orbital Theory, an important concept in quantum mechanics, as well as its application in understanding molecular bonds and antibonds. Topics Covered in Other Articles What is Molecular Orbital Theory? Molecular orbital
Sigma and Pi bonds
Core Concepts In this article, you will learn about the basics of sigma and pi bonds and their importance to organic chemistry. You’ll also have the opportunity to apply what you know with some worked examples. Topics Covered in Other
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
Hybridization and Hybrid Orbitals
Core Concepts In this article, you will learn hybridization, how to identify hybridization orbitals, and the way they affect molecular geometry. Topics Covered in Other Articles What is hybridization? Simply put, hybridization is the way that distinct atomic orbitals combine
What Is A Chemical Bond?
In this article, we look at the types of bonds in chemistry. We explain what is a chemical bond, list the types of chemical bonds, and give chemical bond examples. Bonds are very important in chemistry, as they dictate many
Molecular Structure
Coordination Number in Chemistry
Core Concepts In this article, we learn all about coordination number in chemistry, including its meaning in molecules, metal ion complexes, and crystals. We also discuss the implications of coordination numbers in molecular geometry. Topics Covered in Other Articles What
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,
Complex Ions and Ligands in Chemistry
Core Concepts In this article, we learn about complex ions in chemistry and their ligands, including the various types of complexes, the importance of coordination number, and the chemistry of ligands including ligand substitution reactions. Topics Covered in Other Articles
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
Acids and Bases
Acid Base Neutralization Reactions
What is an Acid Base Neutralization Reaction? An acid base neutralization reaction is when an acid reacts with a base to create water and a salt. The proton (H+) from the acid combines with the hydroxide (OH–) from the base
Acid and Base Indicators
Core Concepts about Indicators Acid and Base indicators are molecules which change color in different pH environments. They are incredibly useful for quickly identifying the pH of a solution. In this article, the basics of Indicators in the context of
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
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
Henderson-Hasselbalch Equation
Core Concepts – Henderson-Hasselbalch Equation In this tutorial, you will learn what the Henderson-Hasselbalch equation is, how to use the equation to determine the pH of a buffer, how to derive the equation, and how to solve some example problems
Titration Curves & Equivalence Point Calculations
Amazing facts about titration analysis, including the types, components, curves, and steps of titrations
Redox Reactions
How to Write Net Ionic Equations
Core Concepts In this tutorial, you will learn how to write net ionic equations. In addition, you will learn how they are useful for understanding which ions in the solution are active in a reaction and which are spectator ions.
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
Electrolytic Cells and Electrolysis
Electrolytic Cells – Core Concepts In this tutorial, we will learn about a second type of electrochemical cell: electrolytic cells. We will also learn broadly about the concept of electrolysis, how it applies to electrolytic cells and chemistry, and its
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
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 –
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
Gases
Gay Lussac’s Law
What is Gay Lussac’s Law? Gay-Lussac’s law is a gas law that states the pressure of a gas varies directly with temperature when mass and volume are kept constant. As the temperature increases, the pressure will also increase. The concept
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,
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
Intro to Gases
Core Concepts In this article, we learn about what a gas is, diatomic gases, the three properties of gases, gas laws, and gas phase changes. Topics covered in other articles What are gases? Gases are the highest-energy state of matter.
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
What is Partial Pressure?
Core Concepts In this article, we learn about partial pressure and it’s 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
Liquids and Solids
Enthalpy of Reaction, Formation, & Combustion
Core Concepts In this article, you will learn the basics of enthalpy, as well as how to use enthalpy of formation to calculate enthalpies of reaction and enthalpies of combustion. Topics Covered in Other Articles Enthalpy Chemists and physicists tend
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
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
Phase Diagrams
Core Concept In this tutorial, you will learn about the major features of phase diagrams, also called phase change diagrams, as well as other types of diagrams, and how to interpret and understand their importance. Topics Covered in Other Articles
What is Specific Heat?
Core Concepts In this chemistry tutorial, you will be introduced to the topic of specific heat. In addition, you will learn the formula that goes along with this concept and go through an example to work out the math. Also,
Exergonic and Endergonic Reactions
Core Concepts In this tutorial, you will learn about exergonic and endergonic reactions and how they describe what happens to energy during a reaction. Topics Covered in Other Articles What is an Exergonic Reaction? In an exergonic reaction, free energy
Equilibrium
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
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.
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
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
Reaction Kinetics
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
Arrhenius Equation
Arrhenius equation- Core Concept 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
Integrated Rate Laws
Core Concepts In this article, we 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 many
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 it’s reaction rate, which is dictated by a rate law. In this article, we will learn about reaction rates, rate laws,
Rate Determining Step
What is the 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
Nuclear Chemistry
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
Alpha, Beta, and Gamma Decay
Core Concepts In this article, we explore the phenomenon of radioactive decay and its most common types: alpha, beta, and gamma decay. Topics Covered in Other Articles What is Radioactive Decay? “Radioactive decay” refers to a group of reactions involving
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
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, we 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” to
Nuclear Processes
Core Concepts In this article you will be able to understand and differentiate both nuclear processes :fusion and fission. After reading this article you will also understand how nuclear energy works and its benefits to the environment. Related Topics Nuclear
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Weak Acids and Weak Bases
Core Concepts In this tutorial, you will learn about weak acids and weak bases, including why they are considered weak and examples of each. We’ll also show you a list of weak acids, and the weakest bases. Topics Covered in
Hybridization and Hybrid Orbitals
Core Concepts In this article, you will learn hybridization, how to identify hybridization orbitals, and the way they affect molecular geometry. Topics Covered in Other Articles What is hybridization? Simply put, hybridization is the way that distinct atomic orbitals combine
Analyse Dimensionnelle
Concepts de base Dans ce tutoriel, vous apprendrez ce qu’est l’analyse dimensionnelle dans le domaine de la chimie, comment l’utiliser, voir des exemples et apprendre comment elle peut être appliquée à la chimie. Sujets abordés dans d’autres articles Qu’est-ce que
What is a Mole and Avogadro’s Number in Chemistry
Core Concepts – Mole in Chemistry 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
Cations and Anions
Core Concepts – Ions, Cations & Anions What are ions? In this tutorial, you will learn about the properties, differences, and examples of ions, cations and anions, as well as how to predict them based on their positions on the
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