객관식An atom's mass number is 13 and its atomic number is 6. How many neutrons are in its nucleus?589views
객관식Carbon-12 and carbon-13 are isotopes of carbon. Which of the following statements is correct?714views
객관식A lithium atom has an atomic number of 3 and a mass number of 7. How many neutrons are in this lithium atom?724views
객관식Which of the following best describes the difference between a diploid cell and a haploid cell?566views