Question

name: _ teacher: _ date: _ q1 chemistry: u2l17 unit 2 review examine the mass spectrum of unidentified r below. use it to answer questions 5 - 7 5. choose the statement below that is true: (a) the average atomic mass of element r is likely closest to 82 amu. (b) all six peaks represent atoms with the same atomic number. (c) peak e represents the isotope with the greatest number of neutrons. (d) there are six ions of element r found in nature. 6. which peak has the greatest relative intensity? what does this mean? (a) peak e; this atom has the greatest relative abundance in nature. (b) peak e; this atom has the greatest number of neutrons. (c) peak f; this atom has the greatest relative abundance in nature. (d) peak f; this atom has the greatest number of neutrons. 7. the identity of element r is: (a) arsenic, as (b) selenium, se (c) mercury, hg (d) thallium, tl 8. which electron - configuration represents an atom in an excited state? a. 1s²2s²2p⁶3p¹ b. 1s²2s²2p⁶3s²2p² c. 1s²2s²2p⁶3s²3p¹ d. 1s²2s²2p⁶3s² 9. *the light produced by signs using neon gas results from electrons that are a. moving from a lower to a higher energy level b. moving from a higher to a lower energy level c. being lost by the ne(g) atoms d. being gained by the ne(g) atoms 10. compared to a sodium atom in the ground state, a sodium atom in the excited state must have a. a greater number of electrons b. a smaller number of electrons c. an electron with greater energy d. an electron with less energy

Explanation:

Step1: Analyze question 5

Peak E has the highest mass - amu value among the peaks. Isotopes with higher mass have more neutrons.

Step2: Analyze question 6

The peak with the greatest relative intensity corresponds to the isotope with the greatest relative abundance in nature. Peak E has the highest relative intensity.

Step3: Analyze question 7

Selenium has isotopes with masses around the values shown in the mass - spectrum.

Step4: Analyze question 8

In an excited - state electron configuration, an electron is in a higher - energy orbital than normal. For 1s²2s²2p⁶3p¹, an electron has jumped from the 3s orbital to the 3p orbital.

Step5: Analyze question 9

When electrons move from a higher to a lower energy level, they emit light.

Step6: Analyze question 10

An atom in an excited state has an electron in a higher - energy orbital compared to the ground state.

Answer:

1. C
2. A
3. B
4. a
5. b
6. c