How to Teach About Electrons in Atoms

Students need to understand electrons to understand a ton of other science topics. For example, lightning happens when electrons in atoms jump between energy levels. All bonding between atoms happens because of the electrons in atoms. Unfortunately, many students don’t have the time or materials to master electrons. Most textbooks have just a few paragraphs on all of the subatomic particles found in atoms.

I like to teach electrons in atoms as an individual unit to reinforce what students have learned in previous units and what they will learn in future units. Since electrons are such a crazy but foundational concept, it is vital that students have a firm grasp of them.

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What are Electrons in Atoms?

Electrons are the negatively charged subatomic particles that orbit around the positively charged nucleus of an atom. While the nucleus is made up of protons and neutrons, only the protons are positively charged. The neutrons have no charge.

Electrons in atoms are so much smaller than protons and neutrons that they do not contribute to the atom’s mass.

In a neutral atom, the number of protons and electrons are equal. With the positive and negative charges cancel out, the atom has no charge. However, if the atom loses or gains an electron, it will have a positive or negative charge.

Energy Levels and Orbitals of Electrons in Atoms

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Electrons in atoms orbit around the nucleus in specific energy levels called electron shells. Scientists number these shells starting with “1,” closest to the nucleus. Electrons move so fast that it is impossible to know precisely where they are, so scientists use orbitals to show where electrons will most likely be found.

The first orbital in every electron shell is the s-orbital. It is a sphere and can hold two electrons. 

The second orbital starts in the second electron shell. It is called the p-orbital and is shaped like a dumbbell. It can hold up to 6 electrons. 

The d and f-orbitals have even crazier shapes and can hold 10 and 14 electrons. The d-orbital starts at the third electron shell, and the f-orbital begins at the fourth electron shell.

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Each circle in this model represents one energy level. We do not usually draw orbitals on atomic models because it would be too hard to understand. Instead, we show all of the electrons in an energy level within one circle around the nucleus of the atom.

The number of electrons shown in an energy level represents all of the orbitals in the energy level. For example, the second ring has eight electrons because two electrons are in the s-orbital and six electrons are in the p-orbital.

Valence Electrons

The outermost shell is called the valence shell, and the electrons in it are called valence electrons. Only valence electrons react with other atoms.

Neutral atoms have the same number of protons and electrons. Neutral means the atom has no positive or negative charge. However, an atom isn’t stable unless its valence shell is full. The only atoms that are both neutral and stable are noble gases because their valence shells are full when their protons and electrons are equal.

Ions

Every other atom must lose, gain, or share electrons to fill its outer shells. If an atom loses an electron, it becomes a positive ion because it has more positively charged protons than negatively charged electrons.

If an atom gains an electron, it becomes a negative ion because it has more negatively charged electrons than positively charged protons.

Ionic Bonds

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Just like protons and neutrons, positive ions, called cations, and negative ions, called anions, are attracted to each other. 

Once sodium gives its electron to chlorine, it becomes a cation, and chlorine becomes an anion. The positive and negative charges pull the atoms together to form a compound called sodium chloride. 

You probably eat sodium chloride every day! It is table salt.

A bond between two ions is called an ionic bond.

Covalent Bonds

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Atoms can also share electrons. Neither atom gives up any electrons. Instead, they move close together, and the electrons orbit both atoms.

In this model, two hydrogen atoms share electrons with an oxygen atom. Now, the hydrogen atoms feel like they have two valence electrons for a full valence shell, and the oxygen feels like it has eight valence electrons for a full valence shell. The three atoms combine to form one molecule of water so that all of the atoms are stable.

Electrons in Atoms Digital Science Unit

If all of this feels overwhelming, you are right! This is a lot of information to learn. So, how do we help our students learn about electrons in atoms? The best way is to put them in control of their learning because we learn best when we are curious, so we want our students to be curious as they explore a new topic.

Of course, our students need guidance too because they don’t know what they don’t know. That’s why I create digital science units for middle school students. The digital science unit provides students with the structure and freedom they need to learn about electrons in atoms.

In all of my digital science units, I include links to related videos so that students can choose how they learn. I also include review and reflection activities to strengthen students’ neural networks on the given topic. Students can do everything in the unit independently, so they are learning the way that works for them, and you have time to support students who need help.

You can check out every page of my electrons in atoms digital science unit in the video below. If you like it, then you can get it at Teachers Pay Teachers.

Does it look like something you need in your classroom? Click the picture below to get it at Teachers Pay Teachers.

Chemical Reactions

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