Question

1. refer to the 3 stable isotopes of argon above. as the mass number of an argon isotope increases from 36ar to 40ar, the number of protons in the nucleus of these atoms a. increases b. doubles c. remains the same d. decreases 3. atoms in the ground state have equal numbers of protons and electrons. atoms with more electrons than protons have a. a positive charge b. a negative charge c. no electric charge d. a higher percent abundance 4. electrons are — a. colliding b. moving in circles c. flying d. appearing in certain areas 5. choose the correct bohr model representation of an atom of chlorine

Explanation:

1. Isotopes have the same number of protons but different numbers of neutrons, so the number of protons in the nucleus of these atoms remains the same.
2. Atoms in the ground - state are neutral overall. Protons have a positive charge, electrons have a negative charge, and in a neutral atom, the number of protons equals the number of electrons.
3. Electrons in an atom are not colliding. According to the Bohr model, electrons move in fixed circular orbits around the nucleus.
4. Chlorine has an atomic number of 17. The first shell can hold 2 electrons, the second shell can hold 8 electrons, and the third shell has 7 electrons for a neutral chlorine atom. The correct Bohr - model representation should show this electron - shell distribution.

Answer:

1. C. remains the same
2. A. a positive charge
3. B. moving in circles
4. C. (the diagram with 2 electrons in the first shell, 8 in the second shell and 7 in the third shell)