Arrange arsenic, cesium, florine, helium, phosphorus, stratium in increasing ionization energy order for 1st ionization energy
To arrange the elements in increasing order of their 1st ionization energy, we need to understand what ionization energy means.
Ionization energy refers to the amount of energy required to remove an electron from a neutral atom, resulting in the formation of a positively charged ion (cation).
The general trend for ionization energy across a period (horizontal row) in the periodic table is that it increases from left to right. This is because, as we move from left to right across a period, the number of protons in the nucleus increases, resulting in a stronger attraction between the nucleus and the electrons in the outermost energy level. It becomes harder to remove the outermost electron as the attraction between the electron and the nucleus increases.
Let's arrange the elements you provided in increasing order of their 1st ionization energy:
1. Helium (He) - Helium is a noble gas and has a full valence shell of electrons. It has the highest ionization energy among the given elements.
2. Fluorine (F) - Fluorine is a halogen and has a high electronegativity due to its small atomic size. This makes it more difficult to remove an electron from fluorine compared to the remaining elements.
3. Phosphorus (P) - Phosphorus is a non-metal and exhibits a moderate ionization energy. It has a larger atomic size compared to fluorine, making it easier to remove an electron.
4. Arsenic (As) - Arsenic is a metalloid and has a larger atomic size compared to phosphorus. Its ionization energy is lower than that of phosphorus.
5. Strontium (Sr) - Strontium is an alkali earth metal and has a lower ionization energy as compared to the previous four elements.
6. Cesium (Cs) - Cesium is an alkali metal and exhibits the lowest ionization energy among the given elements. It has the largest atomic size, which makes it easier to remove an electron.
Therefore, the increasing order of the 1st ionization energy for the elements you provided is: Helium < Fluorine < Phosphorus < Arsenic < Strontium < Cesium.