18Ar is how it is represented on the Periodic Table. It is also known as a Noble gas.
I don't think argon has any other names, but it comes from argos, which is Greek for inactive.
Noble or inert gases
Argon is an inert gas; up today only 3-4 unstable compounds are known.
Not under normal circumstances.
Helium, Neon, Argon and if another Krypton.
Argon and helium are both noble gases, which are generally inert and do not readily form chemical bonds with other elements. Therefore, argon and helium do not typically form chemical compounds with each other or with other elements.
One disadvantage of argon is that it is relatively expensive compared to other gases. Another disadvantage is that it can displace oxygen in a closed environment, which can be dangerous for humans. Argon also has limited reactivity and is not suitable for some welding applications that require a reactive gas.
The group that argon belongs to is the Noble Gases, otherwise known as the inert gases. However, Noble gases is the more acceptable term nowadays because the description inert implies that they cannot be reacted with. These Noble Gases such as argon can be reacted with, but they need incredibly extreme conditions to do such.
Argon is an element and all the atoms in argon are argon atoms.
Atoms of argon have a full outer (valence) shell, and this is why argon is inert. The electrons of an atom have different energy levels. It's conventional to call each collection of possible states of electrons for a given energy level a shell. Shells have finite capacity and argon has a full outer shell. Chemical reactions tend to rely on electrons jumping from one atom to another or two sharing the orbit of 2 electrons (a type of shell around 2 electrons if you like). If the shells are full it is usually more energy efficient for an electron to stay put rather than jump to another atom. consequently argon with its full shells rarely bonds.
Deveroce is probably too strong a term regarding their relationship. In a milder term, such as blood-let, Henry probably found Catherne of Argon stealing oil from her company. I'm guessing Henry was her boss, or maybe a jealous lover who couldn't let his affair get in the way of advancing his career. She probably got in the way when she took oil from Argon. This is probably the truth.
The element Argon has 8 Isotopes argon-35, argon-36, argon-37, argon-38, argon-39, argon-40, argon-41 and argon-42.The stable isotopes of argon are:argon-36, 0.34%argon-38, 0.06%argon-40, 99.60%Of the radioactive isotopes argon-39 has the longest halflife at about 260 years, all the others have halflives measured in days or much less.