How does 2s orbital differ from 1s?

Hint: Atom is the smallest unit of matter in nature. The atom comprises electrons in the orbitals; neutrons and protons in the nucleus. The orbitals present in an atom are s, p, d and f according to the energy differences they have amongst them.

Complete step by step answer:
Let us see the two orbitals i.e. 1s and 2s in detail;
1s orbital-
- This orbital has the lowest energy among all the corresponding orbitals and is located closest to the nucleus. The radius of 1s will be smaller than that of other orbitals i.e. it would be a smallest sphere. Electrons will be firstly filled into the 1s orbital as compared to other orbitals.

2s orbital-
- This orbital will have higher energy than that of 1s whereas, will be less energetic than other orbitals. It would be the next closest orbital from the nucleus after 1s orbital. The radius of 2s orbital will be larger than that of 1s orbital. After 1s, the electrons will fill us 2s orbital.
- Here, ‘n’ in the term ‘ns’ determines the principal quantum number and ‘s’ represents the subshell; the shape of the orbital. The s orbitals are spherically symmetrical amongst the nucleus of an atom
- The most important difference between these two orbitals is that the probability of finding the electron decreases as we move away from the nucleus. Thus, the probability will be more in 1s orbital but will decrease in 2s orbital.

Note: The energy of the orbitals can be calculated by n + l rule which will prove the fact of energy differences between the 1s and 2s orbitals. Also, do note that the radial node will be present in 2s orbital.