The mass number of argon is 40. Which one of the following statements

The mass number of argon is 40. Which one of the following statements is correct?

[amp_mcq option1=”The number of protons in argon is 22.” option2=”The number of neutrons in argon is 18.” option3=”The number of electrons in argon is 18.” option4=”The sum of numbers of protons and electrons in argon is 40.” correct=”option3″]