Question

test: covalent compounds
how many valence electrons do the following atoms want?
most atoms
hydrogen
helium
boron

Explanation:

• For most atoms, the octet rule applies, meaning they want 8 valence electrons to have a stable electron configuration like noble gases.
• Hydrogen has a duet rule. Its valence shell is the first shell (\(n = 1\)), which can hold a maximum of 2 electrons. So hydrogen wants 2 valence electrons.
• Helium is a noble gas. Its electron configuration is \(1s^{2}\). The first shell (\(n=1\)) is full with 2 electrons, so it wants 2 valence electrons.
• Boron often forms compounds with 6 valence electrons. For example, in \(BF_{3}\), boron has 6 electrons in its valence shell (it is an exception to the octet rule in some common compounds).

Answer:

most atoms: 8, hydrogen: 2, helium: 2, boron: 6