Which are more reactive boron helium neon or argon?

Answer 1

These are the noble gases, which means that they have valency 0. The noble gases, or inert gases, have a full outer shell of electrons. This means that they have no spontaneous incentive to enter into compounds with other elements or each other. There are extremely few known compounds that include a noble gas. It is true that noble gases are electrically neutral, but then so are all elements unless something is done to them, like very high temperatures or electric discharges. A noble gas in a discharge tube behaves like any other element. If you doubt this, look at a neon sign ! The difference between inert gases and other elements has nothing to do with neutrality of charge. It is quantum mechanical in nature. Any electron orbit will hold only so many electrons; in a filled orbit all the electrons "feel comfortable". If the outer orbit holds one too few to be full, it has a vacancy for one more to get comfortable. If the outer orbit has only one, the loan of one electron to some other atom empties the outer shell, leaving a new outer shell which is full, and thus also comfortable This makes it very easy to understand a molecule like NaCl, common salt. Sodium has one electron in its outer shell and chlorine has seven. When sodium lends an electron to chlorine each atom then has a full outer shell. Since the sodium now has one fewer electron than protons it has a positive charge. The chlorine atom now has a negative charge because it gained an electron; this causes the two atoms to stick tightly together as a molecule of salt. If a noble gas were to lend an electron, or to borrow one, it would not be "comfortable" in a quantum mechanical sense.

Answer 2

there are 8 valence electrons in argon

Answer 3

boron

Answer 4

8