What is the mass number of an element that has 19 protons, 19 electrons, and 20 neutrons?
A. 19.
B. 39.
C. 38.
D. 20.
Show Answer
Answer: B
Share your understanding of this question with the correct explanation.
What is the mass number of an element that has 19 protons, 19 electrons, and 20 neutrons?
A. 19.
B. 39.
C. 38.
D. 20.
Answer: B
Share your understanding of this question with the correct explanation.