The Symbol for a Certain Isotope of Strontium Is ${ } _ { 38 } ^ { 90 } \mathrm { Sr }$

question 140

Multiple Choice

The symbol for a certain isotope of strontium is ${ } _ { 38 } ^ { 90 } \mathrm { Sr }$ . What is the mass number of this isotope?

• A) 128
• B) 90
• C) 38
• D) 88
• E) 52

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Definitions:

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