Final answer:
The exponent in the electron configuration notation indicates the number of electrons in a subshell, such as in 1s², which means two electrons are in the 1s subshell.
Step-by-step explanation:
The exponent in the electron configuration notation represents the number of electrons in a given subshell. For instance, when we see the notation 1s² 2s² 2p⁶, this specifies the electron distribution in an atom. Here, the 1s² indicates that there are two electrons in the 1s subshell, 2s² signifies two electrons in the 2s subshell, and 2p⁶ identifies that there are six electrons in the 2p subshell. The numbers before the letters 's' and 'p' denote the principal quantum number, which indicates the shell, and the letters themselves refer to the type of subshell. This representation is known as the spectroscopic notation or the electron configuration of an element.