Concept:
Correct spelling is essential in English. Many words are commonly misspelled due to incorrect placement or omission of letters.
Step 1: Examine each option.
Vacum $\rightarrow$ Missing a letter (incorrect)
Vaccum $\rightarrow$ Extra letter (incorrect)
Vacuum $\rightarrow$ Correct spelling (correct)
Vacume $\rightarrow$ Incorrect ending (incorrect)
Step 2: Identify the correct spelling.
The correct spelling is "Vacuum".