General Chemistry

Iron (Fe) is an element found in the d-block of the periodic table, which is commonly referred to as the transition metals. To determine the number of valence electrons in iron, we need to consider its electronic configuration. The electronic configuration of an atom can be determined from its atomic number, which for iron is 26. This means iron has 26 protons and, in a neutral atom, 26 electrons. The electronic configuration of iron can be written using the Aufbau principle, which fills the atomic orbitals from the lowest to the highest energy levels. The electronic configuration of iron is: $$ 1s^2 \, 2s^2 \, 2p^6 \, 3s^2 \, 3p^6 \, 3d^6 \, 4s^2 $$ However, when we talk about valence electrons for transition metals, we generally consider the electrons in the outermost shell as well as the d-subshell electrons from the penultimate shell, since these electrons can be involved in bonding. In the case of iron, the outermost shell is the 4th shell, which contains 2 electrons in the 4s orbital. The penultimate shell is the 3rd shell, which contains 6 electrons in the 3d orbital. Therefore, the valence electrons of iron are the sum of the electrons in the 4s and 3d orbitals: $$ 4s^2 + 3d^6 = 2 + 6 = 8 $$ So, iron has 8 valence electrons. These are the electrons that can be involved in the formation of chemical bonds and in the chemistry of the element.

Question

How many valence electrons does iron have?

PrepMate

Ask a tutor

If you have any additional questions, you can ask one of our experts.