Question

1. isotopes are atoms of the same element that have: a) different numbers of protons b) different numbers of neutrons c) different atomic numbers 10. the periodic table arranges elements by: a) atomic mass b) atomic number c) number of neutrons 11. which subatomic particle has almost no mass? a) proton b) neutron c) electron 12. what does the average atomic mass take into account? a) only the mass of the protons b) the weighted average of all isotopes c) the number of electrons in an atom 13. the electric cloud is best described as: a) the nucleus of the atom b) the area where electrons are likely to be found c) the region containing neutrons 14. how are elements in the periodic table grouped? a) by their properties and electron configuration b) randomly c) by their mass number only 15. which particle determines the identity of an element? a) neutron b) proton c) electron 16. which of these is a correct statement about isotopes? a) they have the same number of electrons b) they have different numbers of electrons c) they have the same number of protons

Explanation:

• 9. Isotopes are atoms of the same element with the same number of protons but different numbers of neutrons.
• 10. The periodic table arranges elements by atomic number.
• 11. Electrons have almost negligible mass compared to protons and neutrons.
• 12. The average atomic mass is the weighted - average of all isotopes of an element.
• 13. The electron cloud is the area where electrons are likely to be found.
• 14. Elements in the periodic table are grouped by their properties and electron configuration.
• 15. The number of protons determines the identity of an element.
• 16. Isotopes have the same number of protons.

Answer:

1. b) Different numbers of neutrons
2. b) Atomic number
3. c) Electron
4. b) The weighted average of all isotopes
5. b) The area where electrons are likely to be found
6. a) By their properties and electron configuration
7. b) Proton
8. c) They have the same number of protons