oxygen, sulphur and selenium
If the first energy level is complete with two electrons, then the elements hydrogen and helium have two elements in their electron configuration. Hydrogen has one electron in its first energy level, while helium has two electrons filling its first energy level.
All elements except hydrogen have two electrons in the first energy level.
For hydrogen (atomic number 1), there is 1 electron in the first energy level. For helium (atomic number 2), there are 2 electrons in the first energy level. For lithium (atomic number 3), there are 2 electrons in the first energy level and 1 electron in the second energy level. For beryllium (atomic number 4), there are 2 electrons in the first energy level and 2 electrons in the second energy level. For boron (atomic number 5), there are 2 electrons in the first energy level and 3 electrons in the second energy level.
A period is a horizontal row on the periodic table of the elements. There are seven periods on the periodic table. Each period corresponds to the highest energy level that contains electrons. For example, the elements in the first period have electrons in the first energy level, which is the only energy level available; the elements in the second period have their highest energy electrons in the second energy level; the elements in the third period have their highest energy electrons in the third energy level, and so on.
The first energy level contains one s orbital, which can hold up to two electrons.
Two electrons can be housed in the first energy level.
When these elements have five electrons on the outermost shell of electrons.
The first energy level can hold up to 2 electrons.
the outermost energy level! ( :
Zinc has 2 electrons on its first energy level.
Group 8A elements have 8 valence electrons. This means that the highest occupied energy level in Group 8A elements will have 8 electrons, as the maximum number of electrons in an energy level is 8 based on the octet rule.
Lithium has a total of 3 electrons. The first energy level of an atom can hold a maximum of 2 electrons, so the first energy level of lithium will have 2 electrons.