No, an element cannot have a negative relative atomic mass. The relative atomic mass, also known as the atomic weight, is a positive value that represents the average mass of the naturally occurring isotopes of an element, taking into account their abundances.
The atomic weight is calculated by multiplying the atomic mass of each isotope by its relative abundance and summing up these values. The result is always a positive value because both the atomic mass and the relative abundance are positive quantities.
However, it's important to note that some elements may have multiple isotopes with significantly different atomic masses. In such cases, the atomic weight may not be a whole number and can be expressed as a decimal. For example, the atomic weight of chlorine is approximately 35.45 amu, indicating the average mass of the different isotopes of chlorine.
While an element cannot have a negative atomic weight, it is possible for some atomic masses of individual isotopes to be negative due to experimental errors or other anomalies. However, these cases are extremely rare and generally considered to be outliers or measurement inaccuracies. In normal circumstances, atomic masses are positive values.