Question

part iv) answer the following questions:

1. which statement describes how an atom in the ground state becomes excited?

a) the atom absorbs energy, and one or more electrons move to a higher electron shell.
b) the atom absorbs energy, and one or more electrons move to a lower electron shell.
c) the atom releases energy, and one or more electrons move to a higher electron shell.
d) the atom releases energy, and one or more electrons move to a lower electron shell.

1. a bromine atom in an excited state could have an electron configuration of

a) 2 - 8 - 18 - 6 c) 2 - 8 - 17 - 7
b) 2 - 8 - 18 - 7 d) 2 - 8 - 17 - 8

1. the characteristic bright - line spectrum of an element is produced when electrons

a) absorb energy and return to lower energy levels
b) absorb energy and move to higher energy levels
c) release energy and return to lower energy levels
d) release energy and move to higher energy levels

Explanation:

1)

• When an atom in the ground state becomes excited, it must absorb energy.
• Electrons move to a higher - energy electron shell (higher electron shell means higher energy level).
• Option a: The atom absorbs energy, and one or more electrons move to a higher electron shell. This is correct.
• Option b: Moving to a lower shell would be de - excitation (releasing energy), so this is wrong.
• Option c: Releasing energy is not for excitation, so this is wrong.
• Option d: Releasing energy and moving to a lower shell is de - excitation, so this is wrong.

3)

• The atomic number of bromine is 35. The ground - state electron configuration of bromine is \(2 - 8 - 18 - 7\).
• In an excited state, an electron moves to a higher energy level.
• Option a: \(2 - 8 - 18 - 6\) has one less electron in the outermost shell (compared to ground state), which is not an excited - state configuration.
• Option b: \(2 - 8 - 18 - 7\) is the ground - state configuration.
• Option c: \(2 - 8 - 17 - 7\) has one less electron in the third shell (compared to ground state), which is not an excited - state configuration.
• Option d: \(2 - 8 - 17 - 8\) shows that an electron has moved from the third shell (which can hold up to 18 electrons in a more complex model for excited states in this context) to a higher - energy level (the fourth shell).

5)

• Bright - line spectra are produced when electrons return to lower energy levels.
• When electrons return to lower energy levels, they release energy in the form of light (photons).
• Option a: Absorbing energy is for excitation, not for producing bright - line spectra.
• Option b: Absorbing energy and moving to higher levels is excitation, not for producing bright - line spectra.
• Option c: Release energy and return to lower energy levels. When electrons do this, they emit light of specific wavelengths (producing the bright - line spectrum).
• Option d: Moving to higher levels requires energy absorption, not release.

Answer:

1. a. The atom absorbs energy, and one or more electrons move to a higher electron shell.
2. d. \(2 - 8 - 17 - 8\)
3. c. release energy and return to lower energy levels