The mass of a single calcium atom is approximately 40.08 atomic mass units (amu), which is roughly equivalent to 6.64 × 10-23 grams.
To understand this, it’s important to know that the atomic mass unit (amu) is a standard unit that quantifies mass on an atomic or molecular scale. For calcium, its atomic mass reflects the weighted average of all its natural isotopes, which accounts for the different masses and relative abundances of these isotopes found in nature.
When converted to grams, the mass of an atom becomes extremely small, as seen with calcium’s mass of about 6.64 × 10-23 grams. This value is impractical for most scales we encounter in daily life, but it is fundamental in chemistry and physics where we deal with quantities on the atomic level.