Chemistry is EASY!

How to:

1. Write electron configurations
2. Balance chemical equations
3. Do mole chemistry (or molar math)
4. Draw Bohr diagrams
5. Understand the atomic model
6. Find chemistry PowerPoint presentations to make chemistry easy
7. Prepare students for the state chemistry test!
  .....(Site updated: November 16, 2010)

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How to write Electron Configurations:

An electron configuration is a shorthand description of how electrons are arranged around the nucleus of an atom. Here is an example of an electron configuration. This particular configuration is for the ground state of iron (Fe).:

Electron Configuration for the ground state of iron:  1s2 2s2 2p6 3s2 3p6 4s2 3d6

According to our modern atomic model, the "quantum mechanical" model, electrons hover and vibrate back and forth within certain defined spaces, somewhat like a bee hovers around a flower. The electron configuration tells exactly where each electron "hovers" in an atom and how much energy it has. The secret to writing electron configurations is to (1) understand the meaning of the numbers and (2) know the pattern of how electrons are added to atoms. It's EASY!

Learn more about how to write electron configurations.

How to Balance Chemical Equations:

Every single atom which goes into a chemical reaction must come out the other side, even though the atoms may be arranged differently. There is no such thing as "losing atoms" in a chemical reaction. Here is an example of the balanced chemical equation for the formation of water:

the balanced chemical equation for the synthesis of water:  2 H2 + O2 --> 2 H2O

The key to balancing chemical equations is to understand the meaning of two numbers: the coefficient and the subscript. Once you know that, balancing equations will be no problem. It's actually EASY!

Learn more about how to balance chemical equations.

What is the Mole in Chemistry? The mole is the name for a number, just like a dozen is the name for the number 12. But the number of a mole is a VERY LARGE number. Here is the number:


Understanding "the mole" is EASY! Read this number and learn more about the mole in chemistry.

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How to do "Mole Chemistry" (or Molar Math):

The unit of a mole, as described in the previous box, is used all the time in chemistry math. Just as we calculate miles/gallon and miles/hour, chemists calculate the grams/mole, atoms/mole and moles/Liter. In addition, the unit of "mole" is used in all kinds of chemical calculations. Here is an example of chemistry math using the unit "mole." (This is a calculation of how many grams of oxygen gas will be needed if 4.5 grams of hydrogen gas is used in a reaction with oxygen to make water.)

mathematical set up for finding the number of grams of O2 needed to react with 4.5 g of H2.  The sequence of factors are:  (4.5 g H2) x (1 mol H2/2.0 g H2) x (1 mole O2/2 mol H2) x (32.0 g O2/1 mol O2) = 36.0 g O2.  Grams of H2 cancel.  mol H2 cancel.  mol O2 cancel.  We are left with grams of O2, which are the units in our answer.

Believe it or not, doing this kind of chemistry math is EASY!
Learn more about how to do
molar math in chemistry.

How to draw Bohr Diagrams: Bohr diagrams show electrons orbiting the nucleus of an atom somewhat like planets orbit around the sun. In the Bohr model, electrons are pictured as traveling in circles at different levels, depending on which element you have. (In real life, electrons do NOT travel in circles as pictured in Bohr Diagrams, but the diagrams are very useful for discussing certain aspects of chemical behavior, so we use them frequently for that purpose.) Here are some examples of Bohr diagrams: (These show the atoms lithium, fluorine and aluminum.)

Bohr diagrams of Lithium, Fluorine and Aluminum.  Lithium has a +3 charge showing in its nucleus representing the 3 protons of lithium.  Two of lithium's electrons are found in the first circle of the Bohr diagram, representing the first layer of electrons.  Because the first layer of electrons is filled with only 2 electrons, the first circle is drawn with a solid line.  The second circle, which is unfilled, contains 1 electron and is represented with a dotted line.  Fluorine has 9 protons in its nucleus.  The first circle is again solid with 2 electrons.  The second circle is dotted with 7 electrons.  A total of 9 electrons balances the 9 protons in the nucleus of fluorine.  Aluminum has 13 protons and 13 electrons.  The first two electrons are in the first circle, which is drawn with a solid line.  The next circle is filled with 8 electrons (4 pairs) and is also drawn with a solid line.  The third circle of aluminum is unfilled, containing only 3 electrons and is represented by a dotted line.

Drawing Bohr diagrams is REALLY EASY! You just have to know how to count. To learn more about drawing Bohr diagams, click here. [Not yet active.]

Understanding the Atomic Model:

Actually, there are several "models" of the atom, not just one. The reason we talk about a "model," rather than about an atom directly, is because we can't really SEE an atom, so we can only guess about how it actually works inside. When our model makes sense and seems to explain what we see when we do an experiment, we say that our model is good. If our model doesn't explain what we see, then we have to change our model until it does explain what we see. Here are several models of the atom as they were developed in history:

Dalton's Model, Hard Sphere represented by a solid circle. ............Thomson's Model, the Plum Pudding model, is a circle with positive charges distributed randomly throughout and negative charges shown in small circles, also distributed randomly like raisins in plum pudding....... Rutherford's model, Mostly Empty Space, is a circle with the positive charges located in a tiny nucleus in the center of the atom with electrons in the rest of the space.

Bohr's model, Planetary atom, is pictured as the positive charges in the center with electrons orbiting the atom in defined circles as planets orbit the sun.................Quantum Mechanical Model, Electron Clouds, showing a tiny, dense nucleus with dotted circles and pear-shaped lobes representing the different orbitals in which electrons can be found.  This atom is pictured with a fuzzier and less defined background indicating the more open and less defined edges of the atom.

Understanding different atomic models is EASY! For more information, just click here. [Not yet active.]

How to find Chemistry PowerPoint Presentations: Well-designed teaching PowerPoint presentations, especially when accompanied by worksheets to help students maintain attention and record their responses, is of great value to a busy teacher. Many excellent PowerPoint presentations already exist which are available for you to use. Some are free, some are expensive, and some are available at minimal cost. As a teacher, your time is very valuable. If you have top-notch materials, it makes you a better teacher and allows you to help your students more. Here is an example of an exceptionally well done chemistry PowerPoint presentation that uses a worksheet.


Finding excellent chemistry PowerPoint presentations is EASY! To find out more about obtaining teacher resources of great value, click here. [Not yet active.]

How to make Chemistry Easy!: Chemistry does not have to be difficult. To look at some very powerful professionally prepared lesson materials, go to the:

Chemistry is Easy Store.

How to Prepare Students for the State Chemistry Test: I am a chemistry teacher in the state of California and have prepared thorough state test preparation materials. To find out how I prepare my students for the State test, click here. [Not yet active.]

A Note from Lynda: Hopefully this has been helpful. If you see something confusing in this presentation, or if you find errors, or if you have questions, please contact me, Lynda Jones, at My goal is to make chemistry EASY! How am I doing?

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Site updated on November 16, 2010 You may email Lynda directly at