The first 3 energy levels are filled, the 4s and 4p and 4d sublevels are filled, and the 5s and 5p sublevels are also filled. So only the first three energy levels are completely filled. The fourth and fifth energy levels are partly filled.
The electron configuration is 1s22s22p63s23p63d104s24p64d105s25p6 or [Kr]4d105s25p6.
A neutral xenon atom has 8 electron shells with 6 completely filled shells and 2 partially filled shells.
A neutral xenon atom has 54 electrons. Two of its electron shells would be completely filled, with 2 and 8 electrons, leaving 44 electrons in the remaining electron shells.
A neutral xenon atom would have 54 electrons filled in its electron shells.
A neutral atom of calcium has 20 electrons arranged in the electron shells. The electron configuration for calcium is 2-8-8-2. The first two shells (K and L) are completely filled, while the M shell is partially filled with 2 electrons.
A neutral xenon atom has 54 electrons. The electron configuration of xenon is [Kr] 4d^10 5s^2 5p^6, with a total of 8 completely filled electron shells (2 in the first shell, 8 in the second shell, 18 in the third shell, 18 in the fourth shell, and 8 in the fifth shell).
A neutral atom of calcium has 20 electrons. Electrons fill the electron shells in order of increasing energy levels, with the first shell holding a maximum of 2 electrons, the second shell holding a maximum of 8 electrons, the third shell holding a maximum of 18 electrons, and the fourth shell holding the remaining 2 electrons. Thus, three electron shells (the first three shells) would be completely filled by a neutral atom of calcium.
5 shells and no electrons would be left over.
Your question reveals a common confusion between orbitals and shells. Chlorine has three electron shells: the first, second and third. The first shell has just the one orbital, the 1s The second shell has two sub-shells, the 2s and the 2p. There are three p orbitals in the 2p sub-shell. Each orbital can hold two electrons, so there are eight electrons maximum in the second shell. The third shell likewise has two sub-shells, the 3s and the 3p, but the 3p is not completely filled, leaving room for one more electron. When chlorine gains this electron it will become a Cl- ion. This is summed up in the electron configuration 1s22s22p63s23p5.
The moon is very big about 1/4 of the size of the Earth (it looks small because it is a long way away). The moon is also solid (like the Earth) and thus there is no room in it to be filled up with shotgun shells. If the moon was empty then you would have to turn 1/4 of the Earth into shotgun shells to fill the volume the Moon takes up.
Bromine has 35 electrons in its neutral state, and, as it is a halogen, 36 in its most stable ion. So it would have 4 shells, with 2, 8, 18, and 7 electrons in the neutral state, or 2, 8 ,18 and 8 electrons in its stable ion.
One gallon of shells would probobly weigh more than one pound of shells
Helium has two electrons around a nucleus so you would look for an element that has two electrons more then filled shells. Lithium has 2 electrons in a filled shell and 1 electron more so it wouldn't work too well. Beryllium has 2 electrons in a filled shell and 2 electrons more so it would work pretty good. Magnesium has 2 electrons in a filled shell, 8 electrons in the next filled shell and 2 more electrons so it would also work pretty good.