Question

TRY H Vele

Answer 1

Answer:

Al- [Ne] 3s²3p¹

As- [Ar] 4s²3d¹⁰ 4p³

Explanation:

• Electron configuration of an element shows the arrangement of electrons in the energy levels or orbitals in the atom.
• Noble-gas configuration involves use of noble gases to write the configuration of other elements.
• This is done by identifying the atomic number of the element and then identifying the noble gas that comes before that particular element on the periodic table.

• For example:

1. Aluminium: The atomic number of Al is 13. The noble gas before Aluminium is Neon which has 10 electrons. Therefore the remaining 3 electrons fills up the 3s and 3p sub orbitals.

• Thus, the noble-gas configuration of Al is [Ne] 3s²3p¹

     2.  Arsenic, Atomic number is 33

• Noble gas before Arsenic is Ar,. Argon has 17 electrons, then the remaining electrons fills up the 4s, 3d and 4p sub-orbitals.
• Thus, the noble-gas configuration of As is [Ar] 4s²3d¹⁰ 4p³