What is an orbital? Explain the point and boundary surface diagram of orbitals.

(N/A) Orbital: The region in space around the nucleus where the probability of finding an electron is maximum is called an orbital. In each orbital,there is a region where the probability of finding an electron is approximately $90 \%$. For this,$|\Psi|^{2}$ is small,but it gives a definite value for a specific distance from the nucleus. It is not possible to draw any geometrical figure that encloses a region of $100 \%$ probability. Therefore,we draw the figure for $90 \%$ probability of finding an electron.
Point and boundary surface diagram of orbitals: In a point diagram,dots are used to represent the probability density. By clustering these points,the shape of the orbital is visualized. In a boundary surface diagram,a surface is drawn for an orbital within which the value of the probability density $|\Psi|^{2}$ is constant.
Example: The boundary surface diagrams of $1s, 2s, 2p_{x}, 2p_{y}, 2p_{z}$ orbitals are standard representations.