2007-04-01 17:27:40 · 3 answers · asked by ÀÖÑô Õ 1 in Science & Mathematics ➔ Chemistry
The first obtial shell is only big enough to contain 2 electrons. Once there are 2 it is complete as this is the case with helium.
Now in Beryllium, is has an extra 2 electron comparied to helium , but these electrons have to be farer away from the nucleus as the first two occupied the first shell. Since they are farer away they have a bigger orbit and hence there is more space for other electrons to occupie the space as well. Since the shell is not full it is then more easier to withdraw the electrons so that the first orbial shell remains and hence it is less stable.
2007-04-01 17:39:28 · answer #1 · answered by Mr Hex Vision 7 · 0⤊ 0⤋
Helium has two electrons, and the first shell only holds two electrons. So the first shell IS its outer shell, and it's full.
Beryllium is atomic number 4, so it has 4 electrons arranged with two electrons in the first shell and two electrons in the second shell. The second shell can hold 8 electrons, so it is not full with only two electrons. Beryllium reacts with other elements to fix this situation.
2007-04-01 17:32:54 · answer #2 · answered by ecolink 7 · 2⤊ 0⤋
what is heryllium ?
2007-04-01 17:54:53 · answer #3 · answered by wizard 4 · 0⤊ 0⤋