Electrons

Atoms, the building blocks of all matter, are made up of three main types of subatomic particles: protons, neutrons, and electrons. In this detailed explanation, we'll explore electrons in detail. Electrons are fascinating particles that play a key role in how atoms interact with each other to form everything around us. They're incredibly small, have a negative charge, and are found in the space surrounding the atom's nucleus.

What are electrons?

The electron is a subatomic particle that carries a negative electric charge. This charge is known as -1. To understand this, think of how magnets work. We know that opposite charges attract each other. So, an electron with a negative charge will be attracted to something with a positive charge, such as a proton.

In the picture above, you can see electrons moving around a large circle. This large circle represents part of the space around the atom's nucleus. Electrons move around in regions known as electron shells or clouds. While the nucleus is where you'll find protons and neutrons, electrons are outside the nucleus.

How do electrons behave?

Electrons are very special because they don't behave like conventional objects. In classical physics, we can easily measure where things are and how fast they are moving. However, electrons behave according to the rules of quantum mechanics, which are quite different.

One important rule is called the Heisenberg uncertainty principle, which states that we cannot know both the position and momentum of an electron at the same time. Instead, electrons exist in clouds or probability distributions. This means that we can only estimate where the electron is likely to be, rather than being able to tell its exact location. To illustrate this, consider the following:

In this example, the shaded area represents the region where the electron is most likely to be found around the nucleus, but we cannot say for sure where it is at any given time. Just as a cloud may look different when viewed again a few moments later, the position of the electron is always changing.

Energy levels of electrons

Electrons are arranged in an atom by energy levels or shells. These energy levels determine how far the electron is from the nucleus. The closer the energy level is to the nucleus, the greater the attraction due to the positive charge of the proton.

The arrangement of electrons in these shells follows a specific order, which can be simplified as follows:

2, 8, 18, 32...

This means that the first shell can have up to 2 electrons, the second can have up to 8 electrons, the third can have up to 18 electrons, and so on. Here is how we see these shells:

The nucleus is at the center and is surrounded by different energy levels. In the diagram above, the electrons are marked as small color-coded dots on different orbits. In reality, they do not orbit like planets around the sun; this is a simplified model to better understand their arrangement.

Valence electrons and chemical bonding

The electrons in the outermost energy level of an atom are called valence electrons. These electrons determine the chemical properties of the atom, including how it bonds with other atoms to form molecules.

If you think about chemical reactions, they are all about how atoms share or transfer their valence electrons. When atoms give, take, or share valence electrons, they form bonds that can create new substances, such as water or salt.

H2O = water: Oxygen shares its electrons with two hydrogen atoms.
NaCl = salt: Sodium transfers its electron to chlorine, forming an ionic bond.

In this diagram, each red circle represents a hydrogen atom, and the green circle represents an oxygen atom. They share electrons, forming a complete and stable molecule of water, H 2 O

Discovery of electrons

The discovery of the electron was a significant event in science. In the late 19th century, a scientist named J.J. Thomson conducted experiments using a cathode ray tube. During these experiments, he observed that the rays bent toward a positively charged plate. This observation forced him to conclude that there must be negatively charged particles smaller than atoms.

Thomson's discovery was important because it showed that atoms were not indivisible; they consisted of smaller particles. His work on the electron paved the way for our modern understanding of atomic structure.

In the visualization above, you can see a simplified version of Thomson's experiment. The electrons are shown traveling through the tube, attracted to the positively charged side, causing the deflection he observed.

The role of electrons in electricity

Electrons play a key role in electricity. When we talk about electric current, we're talking about the flow of electrons through a conductor. Every time you turn on a light switch or charge your phone, electrons move through wires, creating energy.

To understand this, imagine the electrons as cars traveling through a tunnel. The tunnel allows the cars to move along a path, just as wires allow electrons to flow, creating a current that powers our devices.

In the view above, you can see a series of dots, each representing electrons traveling along a wire, producing an electric current.

Effect of electrons in modern technology

Electrons are at the heart of modern technology. Semiconductors used in electronic devices such as computers and smartphones rely on the properties of electrons to work.

Semiconductors control the flow of electrons to process information. By manipulating the number of electrons moving through them, semiconductors can amplify signals, process data, and store information.

Consider a computer memory chip. It stores data by controlling electrons. The different states of the electrons represent binary data - either 1 or 0. This binary system is fundamental to all digital technology.

Conclusion

Electrons may be tiny, but their role in the universe is huge. They are essential for enabling the chemical reactions that sustain life, the flow of electricity that powers technology, and the processes that allow atoms to bond and form new substances. From building molecules to running computers, electrons are an integral part of our world.

By familiarizing ourselves with how electrons work, we can understand their profound impact on the microscopic level of atoms and the vast technology-driven world around us.

Comments