<span>We have ground strate configurations of electrons,if electrons are filled in order of increasing energy. When there are electrons are in higher orbitals, we have an atom in an excited state.
B, and C are excited states.
In B, 2 electrons can fit in the 4s orbital, and that should fill fully before the 4p orbitals.
In C, the same is true for 5s and 5p
In D, this is not an excited state because 4s fills before 3d</span>
Atomic number refers to the proton number of the atom itself. Number of electrons in an atom (an atom that is not reacted with any other molecules / Just the atom alone), is the same as the number of protons, because each electron has 1 negative charge, and each proton 1 positive charge, where they cancel out on each other to become a neutral charge.
So, when atomic number is 6, proton number is also 6, and number of electrons will also be 6 in that atom.
Hope this helps! :)
<span>The ester that is formed by combining propanioc acid with isopropyl alcohol, using heat and an acid catalyst is isopropyl propanoate.</span>
