Unlike most scientific terms, "quark" does not come from Latin or Greek! It comes from a line in the book Finnegans Wake by James Joyce.
Physicist Murray Gell-Mann chose the name in 1964 because protons and neutrons are made of three parts, matching the "Three quarks" in the quote.
A quark is a fundamental constituent of matter.
We used to think Protons and Neutrons were the smallest particles in the nucleus. But they aren't! They are actually composite particles made of even smaller, truly fundamental particles called quarks glued together.
Quarks behave differently than anything in our daily life.
Quarks come in six types, which physicists call "flavors": Up, Down, Charm, Strange, Top, and Bottom. Normal matter (like us) is mostly made of just Up and Down quarks.
Unlike electrons (-1) or protons (+1), quarks have partial charges.
• Up (u) quark = +2/3 charge.
• Down (d) quark = -1/3 charge.
You can never find a quark all by itself. The force holding them together is so strong that if you try to pull them apart, the energy creates new quarks instead of separating them. They are always found in groups.
Imagine you are baking a cake. You need ingredients like flour, sugar, and eggs. If you look at the universe as a giant bakery, what are the basic ingredients?
For a long time, we thought the ingredients were atoms. Then we realized atoms were made of protons, neutrons, and electrons. Now, we know the recipe is even simpler. Almost all normal matter in the universe—stars, planets, puppies, and pizza—is made of just three things: Up Quarks, Down Quarks, and Electrons. By simply mixing these three ingredients in different numbers, nature builds the entire periodic table of elements.