Number of Electrons in Each Shell
| Shell name |
Subshell name |
Subshell max electrons |
Shell max electrons |
|---|---|---|---|
| K | 1s | 2 | 2 |
| L | 2s | 2 | 2 + 6 = 8 |
| 2p | 6 | ||
| M | 3s | 2 | 2 + 6 + 10 = 18 |
| 3p | 6 | ||
| 3d | 10 | ||
| N | 4s | 2 | 2 + 6 + + 10 + 14 = 32 |
| 4p | 6 | ||
| 4d | 10 | ||
| 4f | 14 |
An atom's electron shells are filled according to the following theoretical constraints:
- Each s subshell holds at most 2 electrons
- Each p subshell holds at most 6 electrons
- Each d subshell holds at most 10 electrons
- Each f subshell holds at most 14 electrons
- Each g subshell holds at most 18 electrons
Therefore, the K shell, which contains only an s subshell, can hold up to 2 electrons; the L shell, which contains an s and a p, can hold up to 2 + 6 = 8 electrons; and so forth. The general formula is that the nth shell can in principle hold up to 2n2 electrons.
Although that formula gives the maximum in principle, in fact that maximum is only achieved (by known elements) for the first four shells (K,L,M,N). No known element has more than 32 electrons in any one shell. This is because the subshells are filled according to the Aufbau principle. The first elements to have more than 32 electrons in one shell would belong to the g-block of period 8 of the periodic table. These elements would have some electrons in their 5g subshell and thus have more than 32 electrons in the O shell (fifth principal shell).
Read more about this topic: Electron Shell
Famous quotes containing the words number of, number, electrons and/or shell:
“It seems to me that there must be an ecological limit to the number of paper pushers the earth can sustain, and that human civilization will collapse when the number of, say, tax lawyers exceeds the world’s total population of farmers, weavers, fisherpersons, and pediatric nurses.”
—Barbara Ehrenreich (b. 1941)
“In many ways, life becomes simpler [for young adults]. . . . We are expected to solve only a finite number of problems within a limited range of possible solutions. . . . It’s a mental vacation compared with figuring out who we are, what we believe, what we’re going to do with our talents, how we’re going to solve the social problems of the globe . . .and what the perfect way to raise our children will be.”
—Roger Gould (20th century)
“Such is the art of writing as Dreiser understands it and practices it—an endless piling up of minutiae, an almost ferocious tracking down of ions, electrons and molecules, an unshakable determination to tell it all. One is amazed by the mole-like diligence of the man, and no less by his exasperating disregard for the ease of his readers.”
—H.L. (Henry Lewis)
“How then can we account for the persistence of the myth that inside the empty nest lives a shattered and depressed shell of a woman—a woman in constant pain because her children no longer live under her roof? Is it possible that a notion so pervasive is, in fact, just a myth?”
—Lillian Breslow Rubin (20th century)