During the period 1811-1886, the halogens were discovered. They are non-metallic elements such as: Fluorine (F), Chlorine (Cl), Bromine (Br), Iodine (I) and astatine (At) which are the members of the halogen family. This family constitutes the group 17 of the periodic table. The word halogens have been derived from the Greek word “Halo” that … Read more
Group 15 of the modified long form periodic table consists of five elements: Nitrogen (N), Phosphorus (P), Arsenic (As), Antimony (Sb) and Bismuth (Bi). These elements are collectively called the elements of nitrogen family. Nitrogen and Phosphorus are non-metals, arsenic and antimony are semi-metals or metalloids: bismuth is metallic although not so strong. Some important … Read more
Group 13 of the long form of the periodic table consists of five elements: Boron (B), Aluminium (Al), Gallium (Ga), Indium (In) and Thallium (Tl). All these elements collectively are named as boron group elements, because Boron (B) is the first element of this group. These elements form the first group of the p-block elements. … Read more
Excitation Potential The energy required to raise an atom from its ground state to an excited state is called the excitation energy. Under normal conditions, hydrogen atoms are usually in their lowest energy state where n = 1. This is called ground state of hydrogen atoms. However, if the atoms are exposed to incident energy … Read more
The ionization energy depends upon the following factors: A) Size of the atom The ionization energy depends on the distance between the electron and the nucleus i.e., size of the atom. The attractive force between the electron and the nucleus is inversely proportional to the distance between them. Consequently, as the size of the atom … Read more