The atomic number of iron is 26. How many maximum number of electron(s) of an iron  atom has/have s = =+1/2 ? 

The atomic number of iron is 26. This means an iron atom has 26 electrons, and we can determine how these electrons are distributed in different orbitals based on the quantum numbers.

Understanding the Quantum Numbers for Iron

The quantum number s defines the spin of the electrons. Specifically, when we talk about iron atomic number, the value of the spin quantum number, s = +1/2, represents one possible spin orientation for electrons in an orbital.

Distribution of Electrons with s = +1/2

• s-electrons: Iron's electron configuration in the s orbitals is 4 electrons that have a spin quantum number of s = +1/2. These electrons are in the 1s, 2s, 3s, and 4s orbitals.
• p-electrons: The 6 electrons in the p orbitals also have a spin quantum number of s = +1/2. These are distributed in the 2p, 3p, and 4p orbitals.
• d-electrons: There are 5 electrons in the d orbitals that also have a spin quantum number of s = +1/2. These electrons are placed in the 3d orbital, as per the electron configuration of iron.

In conclusion, the number of electrons in an iron atom that have the spin quantum number s = +1/2 are a total of 15 electrons, distributed across the s, p, and d orbitals. This configuration is important for understanding the magnetic properties and chemical behavior of iron.