Answer:
There are three types of periods in the modern periodic table: very short periods, short periods, and long periods.
- Very short period contains only two elements, Hydrogen and Helium. These elements have only one shell, and their electrons can only occupy the s-orbital.
- Short periods contain eight elements. The first two elements in a short period can only occupy the s-orbital, while the remaining six elements can also occupy the p-orbital.
- Long periods contain 18 elements. The first six elements in a long period can only occupy the s- and p-orbitals, while the remaining 12 elements can also occupy the d-orbital.
The difference between very short periods and short periods is the number of elements they contain. Very short periods only contain two elements, while short periods contain eight elements. The difference between short periods and long periods is the number of orbitals that can be occupied by electrons in each period. Short periods can only have electrons in the s- and p-orbitals, while long periods can also have electrons in the d-orbital.
Here is a table summarizing the differences between very short periods, short periods, and long periods:
- Period type: Very short period
Number of elements: 2
Orbitals that can be occupied by electrons: s-orbital only.
- Period type: short period
Number of elements: 8
Orbitals that can be occupied by electron: s- and p-orbitals.
- Period type: long period
Number of element: 18
Orbitals that can be occupied by electrons: s-, p-, and d-orbitals