helium has 2 electrons in its 1st orbital. It doesn't have 2nd or 3rd orbitals.
There are two electrons in the first shell of neon. Its complete electronic configuration is 2,8
First orbital can be occupied by a total of 2 electrons and the second orbital can be occupied by a total of 8 electrons. 1s^2 2s^2 2p^6 ( what element is this ? )
Boron has two orbital shells. The first shell contains 2 electrons, while the second shell can hold up to 8 electrons. Boron typically has 5 electrons, with 2 in the first shell and 3 in the second shell.
The Bohr configuration for chlorine is 2-8-7, representing the distribution of its electrons in shells. Chlorine has 17 electrons, so it has two electrons in the first shell, eight in the second shell, and seven in the third shell.
An atom with six protons would be a carbon atom. It would have six electrons, two in the first shell, the 1s orbital, and four in the second shell, two 2s electrons and two 2p electrons. The 2p orbital is further out than the 2s, so depending how detailed you want to be there are either four in the second shell, or two in the 2p orbital.
Electrons don't have levels. They have shells and orbitals. Each shell contains certain orbitals. For example, the first shell contains only the s orbital. The second contains the s and p orbital. The fourth shell has the s, p, and d orbitals.
Your question reveals a common confusion between orbitals and shells. Chlorine has three electron shells: the first, second and third. The first shell has just the one orbital, the 1s The second shell has two sub-shells, the 2s and the 2p. There are three p orbitals in the 2p sub-shell. Each orbital can hold two electrons, so there are eight electrons maximum in the second shell. The third shell likewise has two sub-shells, the 3s and the 3p, but the 3p is not completely filled, leaving room for one more electron. When chlorine gains this electron it will become a Cl- ion. This is summed up in the electron configuration 1s22s22p63s23p5.
Magnesium has 3 outer electron shells. It has 12 electrons with 2 in the first shell, 8 in the second shell, and 2 in the third shell.
K shell (or 1s orbital).
Two electrons can fit into the first orbital shell of any atom.
The electronic structure of lithium (Li) is 1s2 2s1, indicating that it has 3 electrons. The first shell is filled with 2 electrons in the 1s orbital, and the remaining electron is in the 2s orbital of the second shell.
Looking at the electron configuration of carbon (at. no. 6) you have 1s2 2s2 2p2. In the 2 p subshell, you have 1 electron in the 2px orbital, and 1 electron in the 2py orbital and no electrons in the 2pz orbital. So, the answer is that there are TWO half filled orbitals in the carbon atom. This is the case BEFORE hybridization. After hybridization, there are FOUR half filled orbitals which are called sp3 hybrids.