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## How many orbitals are completely filled in an atom that has 18 electrons?

When we write the configuration we’ll put all 18 electrons in orbitals around the nucleus of the Argon atom. In writing the electron configuration for Argon the first two electrons will go in the 1s orbital. Since 1s can only hold two electrons the next 2 electrons for Argon go in the 2s orbital.

## Which orbitals are completely filled?

In the sixth period, the orbitals which are completely filled are…

• A. 6s, 6p, 5d, 5f.
• B. 6s, 6p, 6d, 6f.
• C. 6s, 5f, 6d, 6p.
• D. 6s, 4f, 5d, 6p.

## How many orbitals are completely filled in oxygen?

An oxygen molecule has two unpaired electrons. The way the orbital energies work out, there will be 7 fully occupied MOs (14 electrons), 2 half-occupied MOs (1 electron in each), and 1 empty MO. Therefore, there are 2 orbitals that are singly filled in O2 molecules.

## Why 3f Orbital is not possible?

In the second shell, both 2s and 2p orbitals exist, as it can have a maximum of 8 electrons. In the third shell, only the 3s, 3p and 3d orbitals exist, as it can hold a maximum of 18 electrons. Therefore, the 3f orbitals do not exist.

## Which Subshell does not exist?

Explanation: In the ground state for each energy level: In the 2nd energy level, electrons are located only in the s and p sublevels, so there are no d orbitals. In the 1st energy level, electrons occupy only in the s sublevel, so there is no d sublevel.

## Why 2d and 3f is not possible?

This means that the second shell has only s- and p-orbitals and no d-orbitals are present. Similar for n = 3, the permissible values of l are 0, 1, 2. Thus, only s, p and d orbitals are permitted and no f-orbital is present in the third shell.

## Why is 2s bigger than 1s?

The 2s orbital is larger than 1s orbital. Hence, its radius is larger than that of the 1s orbital. Its energy is higher than 1s orbital but is lower than other orbitals in an atom. 2s orbital also can be filled only with one or two electrons.