Write 0.000043 in scientific notation.

A number is expressed in scientific notation as ${\displaystyle a\times {10}^n}$, where n is an integer and ${\displaystyle 1\le a<10}$ denotes that the number has a single digit to the left of the decimal point. Consequently, 0.000043 may be expressed as ${\displaystyle 4.3\times {10}^{-5}}$. Take notice of the decimal point's five-point rightward movement.