Astatine is a chemical element with the symbol At and atomic number 85. It is the rarest naturally occurring element in the Earth's crust, occurring only as the decay product of various heavier elements. All of astatine's isotopes are short-lived; the most stable is astatine-210, with a half-life of 8.1 hours.

What is the full electron configuration?

The electron configuration is the standard notation used to describe the electronic structure of an atom. Under the orbital approximation, we let each electron occupy an orbital, which can be solved by a single wavefunction. ... These numbers can be thought of as an electron's "address" in the atom.

What does 1s2 2s2 2p6 3s2 mean?

Answer: 1s2 2s2 2p6 3s2 3p4 means that ●s subshell of first orbit or energy level(1s2)has two electrons, ●s su...