Periodicity Flashcards
What is periodicity?
The repeating patterns in the chemical and physical properties of elements across a period of the periodic table.
What is atomic radii?
The distance between the nucleus and outermost electron of an atom.
How is atomic radii measured?
Two atoms of the same element are placed touching side by side and then the distance between the two nuclei are measured and then halved.
What is atomic radii known as in metals and then in non-metals?
Metallic radii and covalent radii
Why is covalent radii used?
It can be obtained in almost all elements of the periodic table.
Trend of atomic radii across a period and why?
Atomic radii decreases across the period. This is due to the increase in nuclear charge despite the constant number electron shells whose shielding effect is not as effective. The increased nuclear charge pulls much greater on the outermost electrons, making the radius of the atom smaller.
Do noble gases have a covalent radius?
No. They have Van der Waals’ radius as they are unable to bond together.
Trend in ionic radii?
Decreases across the period. Cations generally have a lower ionic radius than Anions.
Why do Anions generally have higher ionic radii than Cations?
