Answer:
The atomic mass on the periodic table is a decimal number because it is an average of the different isotopes of an element.
P.S.
An isotope is each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei, and differ in relative atomic mass but not in chemical properties; in particular, a radioactive form of an element.
-Pure magnesium is commonly made by separating it from seawater. This process is known as electrolysis. The liquid magnesium formed is cooled into convenient blocks of metal known as ingots. The chlorine gas is recycled to form hydrochloric acid for the production of more magnesium chloride.
The percentage error is the error of the measured value to the true value. To find he percent error, the equation is as follows:
Percent error = |Measured Value - True Value|/True Value * 100
The || is needed to get the absolute value of the difference. Substituting the values,
Percent error = |(10.085 g/10 mL) - 0.9975 g/mL|/<span>0.9975 g/mL * 100
</span><em>Percent error = 1.1% </em>