Find solutions to your problems with the help of IDNLearn.com's knowledgeable users. Join our interactive Q&A community and access a wealth of reliable answers to your most pressing questions.

The atomic symbol Superscript 40 subscript 19 upper K. represents potassium-40 (K-40), a radioactive isotope that has 19 protons and 21 neutrons. Which atomic symbol could represent an isotope that results from the decay of K-40? Superscript 40 subscript 18 upper A r. Superscript 40 subscript 18 upper K Superscript 42 subscript 20 upper C a Superscript 42 subscript 20 upper K.