18
2
The number of electrons in a shell is 2n2, where n=shell number. So for the first shell, there is a maximum of 2 electrons.
Shell 1: Two electrons Shell 2: Eight electrons Shell 3: Eight electrons Shell 4: Eighteen electrons
First Shell always has 2 electrons. Second shell onwards can have up to a maximum of 8 electrons.
The maximum number of electrons that can be present in each shell or subshell is determined by the formula 2n2, where n is the principal quantum number of the shell or subshell.
2
The number of electrons in a shell is 2n2, where n=shell number. So for the first shell, there is a maximum of 2 electrons.
Shell 1: Two electrons Shell 2: Eight electrons Shell 3: Eight electrons Shell 4: Eighteen electrons
The electronic configuration of Bromine in its ground state is: 1s2 2s2p6 3s2p6d10 4s2p5. Therefore the principal quantum number for the outermost electrons in a Bromine atom is 4.
16 electrons would fill up the first four shells in an atom: 2 electrons in the first shell, 8 electrons in the second shell, 4 electrons in the third shell, and 2 electrons in the fourth shell.
Bromine has 7 electrons in it's outer shell. It can hold eight so, it needs 1 more electron. The answer above is is probably the answer expected, however as the the question says outer shell which sometimes is used to refer to the highest principal quantum number, in bromines case 4, the answer could be 25, as the fourth shell can hold 32 electrons.
There are 4 shells in 20 electrons: 2 electrons in the first shell, 8 in the second, 8 in the third, and 2 in the fourth shell.
First Shell always has 2 electrons. Second shell onwards can have up to a maximum of 8 electrons.
The maximum number of electrons that can be present in each shell or subshell is determined by the formula 2n2, where n is the principal quantum number of the shell or subshell.
The valence shell is the outermost shell of the atom. For example, hydrogen (which is located on Period 1) has only one shell and it is its valence shell. Another example, bromine (which is located on Period 4) has four electron shells, and its fourth shell (counting away from the nucleus) is its valence shell containing seven electrons.
20 electrons would need 4 shells. The first shell can hold up to 2 electrons, the second shell can hold up to 8 electrons, the third shell can hold up to 18 electrons, and the fourth shell can hold up to 32 electrons.
The fourth electron shell is filled by krypton. Krypton is the last element in the fourth period on the periodic table. Each of the periods represents an electron shell. Elements in the first period have electrons in the first shell; elements in the second period have electrons in the second shell; and so on.