Final answer:
The shorthand method for electron configuration uses superscripts to indicate the number of electrons in each sublevel. Arrows are used in orbital filling diagrams, not shorthand notation, which instead utilizes superscripts and includes the principal quantum number and orbital type.
Step-by-step explanation:
When using the shorthand method for showing the electron configuration of an atom, the correct answer is a) Arrows, electrons. However, it is worth noting that the question as presented in the prompt contains a mismatch. Arrows are indeed used in orbital filling diagrams, but when referring to the shorthand (or simplified) electron configuration notation specifically, it's actually superscripts that are used to indicate the number of electrons occupying each sublevel.
The correct description for writing shorthand electron configurations is as follows: each occupied sublevel designation (which includes the principal quantum number and the letter that designates the orbital type) is written followed by a superscript indicating the number of electrons in that sublevel. For example, the electron configuration of lithium would be written as 1s²2s¹. The numbers preceding the letters denote the quantum energy levels, while the letters (s, p, d, f) indicate the type of subshell or orbital.
The superscript number that follows each letter indicates the total number of electrons within that subshell. By following the Aufbau principle, Hund's rule, and the Pauli exclusion principle, this notation simplifies the indication of where electrons are located within an atom. The shorthand notation provides a clear and efficient picture of the electrons' arrangement without the need for extensive orbital filling diagrams involving boxes and arrows.