Charge of a Proton | Universe Today

Written by Tega Jessa

What is a proton? A proton is one of the elementary particles that make up an atom. The proton has a positive charge. The charge is important because it is what holds an atom together. An atom has a pretty general structure. First, there is a nucleus which is the heart of the atom. It is composed of proton and a subatomic particles with a zero charge called neutrons. Around the nucleus is a cloud electrons that are separated in orbits like the Solar System. Electrons have a negative charge. If you have learned about electricity and magnetism, you know that opposite charges attract. So the attraction between the sum total positive charge of the protons and neutrons of the nucleus attracts the negative charge of the electrons. This force of attraction between charged particles on the subatomic level is called the strong-weak force. The existence of protons by themselves outside normal element atoms only occurs naturally in the form of Hydrogen gas atoms. Hydrogen gas has only 1 proton and nothing else in its most abundant form.

The Scientist Ernest Rutherford is believed to be the person who discovered protons. He did an experiment in which he fired charged high energy particles of radiation called alpha particles at a cloud of Nitrogen gas. He discovered that the gas showed traces of Hydrogen even though the experiment was not using that gas. From earlier experiments he new high energy radiation could break down elements so he conclude that since Hydrogen was a byproduct it had to be an elementary particle. This was later called a proton.

The charge of the proton is also very important in chemistry. Most acids are formed by the bonding of Hydrogen protons(i.e. ions) to other elements. Protons are also abudant in plasma one of the four states of matter. Plasma is basically ionized gas and all stars are made of it.

In modern technology protons also play an important part. For example a form of spacecraft propulsion is the ion engine. It works by using protons fired from a device called a cathode ray to ionize a gas into plasma. The plasma is then accelerated out of the engine by an electromagnet to create the thrust that propels the space crafts. This method is now used to propel space probes and help correct the orbit of satellites.

All of this technology is based upon the concept of a positively charged particle called the proton.

If you enjoyed this article there are several others on Universe Today that you will enjoy. There are two interesting articles on fundamental particles and fusion in the Sun.

There are also some great resources on the web. The Georgia State University Physics department has a great web page on protons. There is also an interesting article on Wired.com about proton accelerators.

You can also listen to Astronomy Cast. Episode 116, Molecules in Space, is an interesting episode.

Filed under: Astronomy