if you have an atom of thorium and realise that it has 90 electrons, how many outer layers would it have?

Question

we know that the inner shell can only hold 2 electrons and an outer or secondry shell can only hold up to eight electrons- does this mean that an atom of thorium has 11 outer shells?
and please before the dissinterested souls come back with silly quips - I am trying to learn!

I know that outer shells can only hold 8 electrons,does this hold for each outer shell - i.e. if the atom was comprising of circular or spherical shells -one inside the other, would there be 11 outer shells,one inner shell and the nucleus?

I have found that an outer shell may contain more than 8 electrons - in fact it may contain up to 32 electrons but what I can't understand is how we work out how many are in each shell or even how we work out how many shells the atom has.
Does thorium always have atoms with a set number of shells and how do we know this? if we now know how many shells thorium has - how do we know how many electrons are in each shell i.e. how many are in the 2nd shell, 3rd, 4th and so forth? How do we come to this conclusion?

Answer 1

First shell can hold 2 electrons
Second shell can hold 8 electrons
Third shell can hold 18 electrons
Fourth shell can hold 32 electrons
Fifth shell can hold 50 electrons, etc

This is worked out as the first shell has one orbital, the second has two, the third three, and so on.
The first orbital has one sub shell, the second orbital has three sub shells, the third orbital has five sub shells, etc.
Each sub shell can hold 2 electrons.

Therefore, if the atom needs to hold 90 electrons, it needs 45 sub shells.
if the first shell has one orbital, and one subshell, the second has two orbitals and therefore 4 subshells, we can work out that we would need 5 shells to accommodate 90 electrons

Answer 2

Ok, the full answer is very complicated, however, a simplified answer is that with the exception of hydrogen and helium, the outer shell of each atom has 8 possible spots, but the Lanthanides are very weird. If you are trying to teach yourself how this works, stick to the first 2 columns and the last 6 columns. If you are at college level chemistry or above, it would make more sense to learn how the electron orbits work, because The outer shell being filled with thorium has 14 possible slots, so thorium has 2 electrons in its outer shell.

Again, the periodic table is set up by orbital groupings, you cannot simply say it has 11 outer shells, the electron configuration would be as follows

1s^2, 2s^2, 2p^6, 3s^2, 3p^6, 4s^2, 3d^10, 4p^6, 5s^2, 4d^10, 5p^6, 6s^2, 4f^14, 5d^10, 6p^6, 7s^2, 5f^2.

So the highest energy shell, being the 5 f orbital group, contains 2 electrons.

Answer 3

Thorium (Th) has 7 energy levels or shells as follows: -

Shell 1 or 'K' = 2 electrons
Shell 2 or 'L' = 8
Shell 3 or 'M' = 18
Shell 4 or 'N' = 32
Shell 5 or 'O' = 18
Shell 6 or 'P' = 10
Shell 7 or 'Q' = 2

= 90 electrons. Also has 90 protons.

Atomic mass = 232.

232 - 90 = 142 Neutrons.
Here's some extra info: -

(Each shell is allowed a maximum number of electrons which can be calculated from the formula 2n2 , where ‘n’ is the shell number, (corresponding to the shell identification letter). The following table shows examples of maximum possible number of electrons in each shell using this formula:-

Shell....Number.....Max. No. of Electrons
...K ............1 ............2 x1² = 2
...L ............2 .............2 x 2² = 8
...M ...........3 ..............2 x 3² = 18
...N ............4..............2 x 4² = 32
...O ...........5 ..............2 x 5² = 50 *
...P ............6 ..............2 x 6² = 72 *
...Q ...........7 ...............2 x 7² = 98 *

* = Theoretical Capacity

Is this what you need?

Answer 4

It seems you are at the level wher u assume that every shell besides the innermost has 8 electrons, then 11 is the correct answer.

But if you are at the level where you learnt about orbtals where the first orbital is the s orbital and it holds only 2 electrons, the second a D orbital which holds is it 5, and you have the p orbitals then you have tough luck calculating the answer.

Answer 5

Being pedantic: there can only be one 'outer' shell, regardless of how many shells exist in total.

Trying to be more cooperative: it is assumed that the electrons exist in discrete energy states called orbitals, as explained by earlier answers. The shapes of these orbitals are not spherical shells, but rather are mathematical projections of the electron's energy state as a wave-form.

Answer 6

The Properties of the Thorium Element
Name of Element : Thorium
Symbol of Element : Th
Atomic Number of Thorium : 90
Atomic Mass: 232.0381 amu
Melting Point: 1750.0 °C - 2023.15 °K
Boiling Point: 4790.0 °C - 5063.15 °K
Number of Protons/Electrons in Thorium : 90
Number of Neutrons in Thorium : 142
Crystal Structure: Cubic
Density @ 293 K: 11.72 g/cm3
Color of Thorium : silvery

Answer 7

your right 11 outer shells


Shell - Total
1-2
2-10
3-18
4-26
5-34
6-42
7-50
8-58
9-66
10-74
11-82
12-90

Answer 8

Simple....90. One for each proton.