The no of s electrons present in 55 protons in its unipositive ion

To determine the number of s electrons present in an atom, we need to look at the electron configuration of the element.

First, we need to identify the element with 55 protons. This corresponds to the element cesium (Cs) on the periodic table.

Next, we need to determine the electron configuration of cesium. The electron configuration of an element tells us how the electrons are distributed in the different energy levels or orbitals.

The electron configuration of cesium is: 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^6 5s^2 4d^10 5p^6 6s^1.

From the electron configuration, we can see that cesium has one electron in the 6s orbital. Therefore, the unipositive ion of cesium (Cs+) would have lost one electron, leaving us with the electron configuration of 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^6 5s^2 4d^10 5p^6.

In this configuration, we can see that there are still two electrons in the 6s orbital. Therefore, the number of s electrons present in the unipositive ion of cesium is 2.