First of, Valence electron ground state is the number at the end of a Electron configuration
in period 2 which goes across (from left to right) you see that each element has 2 numbers on the electron configuration ex
Li 2-1 Be 2-2 B 2-3 C 2-4
notice that the ground state (which is the last number is in the secoond shell
(I THINK)
Period 2 elements have their 1s orbital completely filled. The valence electrons are located in the 2s and 2p shells.
Helium. (A hydride ion has the same electronic configuration, but hydride is not an element since it has a net electric charge.)
2
The element boron.
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Calcium has 2 valence electrons and 4 electron shells. It is represented by the chemical symbol Ca.
Two electrons imply that the element is in the second period. The 4 valence electrons says that it is located in group 4A (or group 14 in modern notation). Hence, this element is carbon.The element has 2 electron shells means the element is in the 2nd group. This element is carbon. It has 4 valence electrons.
This element is sulfur; the electron configuration of sulfur is [Ne]3s23p4. Sulfur has three electron shells cotaining 2, 8 and 6 electrons. The last six are valence electrons.
Beryllium (Be) has 4 protons and 2 valence electrons.
4 electrons, 2 valence electrons
Sulphur
Calcium has 2 valence electrons and 4 electron shells. It is represented by the chemical symbol Ca.
Two electrons imply that the element is in the second period. The 4 valence electrons says that it is located in group 4A (or group 14 in modern notation). Hence, this element is carbon.The element has 2 electron shells means the element is in the 2nd group. This element is carbon. It has 4 valence electrons.
Period number = no. of electron shells. Therefore neon has two shells.
Helium has 2 electrons (total of 2 electrons and 2 valence electrons)
This element is sulfur; the electron configuration of sulfur is [Ne]3s23p4. Sulfur has three electron shells cotaining 2, 8 and 6 electrons. The last six are valence electrons.
Helium has 2 electrons and Radon has 86 electrons but both have 8 valence electrons (8 electrons in their outermost shells)
Beryllium (Be) has 4 protons and 2 valence electrons.
4 electrons, 2 valence electrons
There are 2 valence electrons in cobalt.
H, Li, Na, K = 1valence electrons Be, Mg, Ca = 2 valence electrons B, Al = 3 valence electrons C, Si = 4 valence electrons N, P = 5 valence electrons O, S = 6 valence electrons F, Cl = 7 valence electrons He, Ne. Ar = 0 because they are noble gases and all their electron shells are full
Well, the first valence electron shell contains 2 valence electrons, which every element has (with the exception of hydrogen), and all shells afterwards can hold up to 8 electrons. - So, by totaling, an element with 1 energy level full has 2 valence electrons, 2 full would mean 10, 3 full would mean 18, 4 full would mean 26, and so on.