If an atom, ion, or molecule is at the lowest possible energy level, it and its electrons are said to be in the ground state.

Terms in this set (31)

• Aufbau Principle. electrons occupy lowest energy levels first.
• Pauli Exclusion Principle. an atomic orbital can have at most 2 electrons.
• Hund’s Rule.
• atomic orbitals.
• Shapes of orbitals.
• cloud region.
• amplitude.
• hertz (Hz)

Hund’s Rule

Ground State

The lowest energy sublevel is always the 1s sublevel, which consists of one orbital. The single electron of the hydrogen atom will occupy the 1s orbital when the atom is in its ground state.

Answer. The rule that is violated when two electrons in an 2s orbital pocesses same clockwise Spin is pauli’s exclusion principle.

Pauli’s Exclusion Principle states that no two electrons in the same atom can have identical values for all four of their quantum numbers. In other words, (1) no more than two electrons can occupy the same orbital and (2) two electrons in the same orbital must have opposite spins (Figure 46(i) and (ii)).

The Pauli Exclusion Principle states that, in an atom or molecule, no two electrons can have the same four electronic quantum numbers. As an orbital can contain a maximum of only two electrons, the two electrons must have opposing spins.

The quantum spin forces allow two electrons to occupy the same orbital. These forces are also called exchange forces. They are attractive for two electrons with opposite spin and repulsive for two electrons with parallel spins. These forces are the consequence of Pauli’s exclusion principle.

The d sublevels are called 3d and 4d. The only f sublevel we study is the 4f. When we fill electrons into an atom, we start with the 1st level because it is closer to the nucleus and thus lower in energy.

Electrons usually tend to enter the 4s orbital before entering the 3d orbital because if we look at basic principle electrons tend to first occupy orbital with the lowest energy first and once they are filled they move on to enter the higher energy orbitals.

According to Aufbau principle , electrons first occupy the lowest energy orbital available to them and enter into higher energy orbitals only after the lower energy orbitals are filled . Therefore , 3d orbital is higher in energy than 4s . And hence electrons fill up in 4s before filling up in 3d .

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.

Maximum number of orbitals in an energy level (n2)

six electrons