The precise weight of a mole of some pure elements like silicon (Si) can vary slightly from the standard atomic mass, or even from sample to sample. Why?
A) The element may undergo radioactive decay.
B) The element may react with itself and gain or lose subatomic particles.
C) The atoms of the element form chemical bonds with each other, and that changes the weight of the element.
D) The element may have multiple stable isotopes, and the isotopic composition may vary from sample to sample.
E) The amount of energy absorbed by the element affects the mass of its electrons, and thus the atomic mass can vary slightly.
1–12 Elements essential to animal life and health
Estimating the molecular weight of a protein. The electrophoretic mobility of a protein on an SDS po
Elements found in the element cube
Overhead stretch for the shoulder muscles. Lean back to create the stretch using your body weight.
Elements of Culture
Using trace elements in carbonate shells to estimate temperature