Practice MCQ Questions and answers on Chemistry-GK

Fluorine is the most reactive element of all in Group 7.

The element with the lowest electronegativity value is francium, which has an electronegativity of 0.7.

Electronegativity increases from bottom to top in groups, and increases from left to right across periods. Thus, fluorine is the most electronegative element, while francium is one of the least electronegative.

The element with highest ionization potential is helium.

Electronegativity has no unit.

The transition metals have a tendency to lose electrons. Since the electrons in the highest energy level are actually on a lower principal energy number than the ones before them, this makes it relatively easy to lose some or all of their electrons to land in stable state. When these metals form ions, the 4s electrons are always lost first; so, they form only cations (positive ions).

The most electronegative element among the following is Fluorine.

Total number of halogen elements found in the periodic table is 6.

Nitrogen has a half filled orbital. On the other hand, since Oxygen is already unstable relative to Nitrogen, by losing one electron it attains a stable half filled orbital. So oxygen undergoes ionisation at a relatively lower energy. This is why nitrogen has a higher ionisation energy than oxygen.

Halogens are the elements which belong to Group 17 of the periodic table. The atomic number of the elements present in this group are 9, 17, 35, 53 and 85. The elements are Fluorine, Chlorine, Bromine, Iodine and Astatine.