Gallium Has an Average Atomic Mass of 69 ${ }_{31}^{72} \mathrm{Ga}$

question 39

Multiple Choice

Gallium has an average atomic mass of 69.7 amu.In a typical sample,60.4% of Ga exists as Ga-69 (68.9257 amu) .What is the identity and the atomic mass of the other isotope?

• A) \({ }_{31}^{72} \mathrm{Ga}\) ;70.9 amu
• B) \({ }_{31}^{70} \mathrm{Ga}\) ;70.9 amu
• C) \({ }_{31}^{71} \mathrm{Ga}\) ;70.9 amu
• D) \({ }_{31}^{71} \mathrm{Ga}\) ;71.9 amu
• E) \({ }_{31}^{72} \mathrm{Ga}\) ;71.9 amu

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Definitions:

Social Facilitation

The tendency for individuals to perform better on tasks when in the presence of others than when alone.

Wisdom of the Crowd

The phenomenon that collective judgment or decision of a diverse group of individuals is often more accurate than that of any single member of the group.

Ringelmann Effect

The phenomenon where individual productivity decreases as the size of a group increases, often due to coordination and motivation issues.

Anonymity

The state of being anonymous, where an individual's identity is not known or revealed.