Georgia State University (GSU) CHEM 1211K Principles of Chemistry I Test 1 Practice Test

Unlock all questions

This demo includes only 20 questions. Upgrade to access hundreds of questions, flashcards, exam simulations, and disable ads.

Full question bankExam simulationsFlashcards

From $12.50Unlock all

Session length

1 / 20

For the nuclide 25/12 X, how many protons, neutrons, and electrons does the neutral atom have?

p+ = 13, n° = 12, e- = 13

p+ = 12, n° = 13, e- = 12

The key idea is that the top number in a nuclide symbol is the mass number (p+ plus n0) and the bottom number is the atomic number (number of protons). For 25/12 X, the mass number is 25 and the atomic number is 12, so there are 12 protons. Neutrons are mass minus protons: 25 − 12 = 13. In a neutral atom, the number of electrons equals the number of protons, so there are 12 electrons. The counts are protons 12, neutrons 13, electrons 12.

p+ = 11, n° = 14, e- = 12

p+ = 12, n° = 13, e- = 13