The expression "1 x 10^-4" is a way to represent a very small number in scientific notation. It means 1 divided by 10,000, which equals 0.0001. This format is often used in science and mathematics to simplify the writing of small values, making them easier to read and work with. In various fields, such as physics and chemistry, small numbers like 1 x 10^-4 can represent quantities like concentrations or measurements. For example, a concentration of 0.0001 moles per liter indicates a very dilute solution, which is common in experiments and analyses.