Select all that apply. what is common about the elements of a period? they have the same number of electron shells. they have similar chemical characteristics. they have similar physical characteristics. they transition from a metal to noble gas.

The answer is
They have the same number of electron shells
They transition from a metal to noble gas. Electron shells are also referred to as atomic orbitals. The number of electrons increase from left to right of the periodic table (until the orbital shell is filled and the atom becomes stable/noble) while the number of atomic orbitals increases from top to bottom of the periodic table.

The correct answer is b

It is 4.92 e-4 sorry if i am wrong