Ch. 28 Misconceptual Questions

An atom has the electron configuration 1s2, 2s2, 2p6, 3s2, 3p6, 4s1 How many electrons does this atom have? a) 15 b)19 c) 30 d) 46

b) 19 The sum of the number of electrons in Sub shell gives the total number of electrons in that atom. n= 2+2+6+2+1

The Pauli exclusion principle applies to all electrons a) in the same shell, but not electrons in different shells b) in the same container of atoms c) in the same column of the Periodic Table d) in incomplete shells e) in the same atom

e) in the same atom Pauli's exclusion principle states that no two electrons in an atom can have the same quantum numbers that means its it applied to all electrons in the same atom

Which of the following is required by the Pauli exclusion principle? a) No electron in an atom can have the same set of quantum numbers as any other electron in that atom. b) Each electron in an atom must have the same n value c) Each electron in an atom must have different ml values d) Only two electrons can be in any particular shell of an atom e) No two electrons in a collection of atoms can have the exact same set of quantum numbers.

a) Pauli's exclusion principle states that no two electrons in an atom can have the same quantum numbers that means it applies to all electrons in the same atom

If a beam of electrons is fired through a slit, a) the electrons can be deflected because of their wave properties b) only electrons that hit the edge of the slit are deflected c) electrons can interact with electromagnetic waves in the slit, forming a diffraction pattern. d) the probability of an electron making it through the slit depends on the uncertainty principle

a) The electrons can be deflected because of their wave properties A material particle under can exhibit both wave nature and particle nature, according to de Broglie. The diffraction and interference patterns of electron are explained by the concept of wave theory. Whenever a beam of electrons is fired through a slit, the electrons deflected through the slit because of their wave nature.

For the electron configuration of Misconceptual Question 1, what orbital quantum numbers do the electron have? a) 0 b) 0 and 1 c) 0 and 1 and 2 d) 0 and 1 and 2 and 3 e) 0 and 1 and 2 and 3 and 4

b) 0 and 1 The orbital quantum number l indicates Sub shell of the electron s=0 p=1 d=2 f=3 Since the atom has only s orbital and p orbital in its electronic configuration, the orbital quantum numbers of a given atom are 0 and 1

According to the uncertainty principle a) there is always an uncertainty in a measurement of the position of a particle b) there is always an uncertainty in a measurement of the momentum of a particle. c) there is always an uncertainty in a simultaneous measurement of both the position and momentum of a particle d) All of the above

c) Heisenberg's uncertainty principle states that the position and momentum of a microscopic particle cannot be determined simultaneously. If you know the position or the momentum of a particle accurately, we cannot measure these two observables simultaneously to an arbitrary accuracy. If you know one of these quantities accurately, we can measure uncertainly of the other quantity only.

Which of the following is the best paraphrasing of the Heisenberg uncertainty principle? a) Only if you know the exact position of a particle can you know the exact momentum if the particle b) The larger the momentum of a particle, the smaller the position of the particle c) The more precisely you know the position of a particle, the less well you can know the momentum of the particle d) The better you know the position of a particle, the better you can know the momentum of the particle e) How well you can determine the position and momentum of a particle depends on the particle's quantum numbers.

c) Heisenberg's uncertainty principle states that the position and momentum of a microscopic particle cannot be determined simultaneously. If you know the position or the momentum of a particle accurately, we cannot measure these two observables simultaneously to an arbitrary accuracy. If you know one of these quantities accurately, we can measure uncertainly of the other quantity only.

What is meant by the ground state of an atom? a) All the quantum numbers have their lowest values (n=1, l=ml=0) b) All the principle quantum number of the electrons in the outer shell is 1 c) All of the electrons are in the lowest energy state, consistent with the exclusion principle. d) the electrons are in the lowest state allowed by the uncertainty principle

c) All of the electrons are in the lowest energy state, consistent with the exclusion principle The ground state of an atom is the lowest possible energy state and the arrangement of electrons in their respective shells must obey the Pauli's exclusion principle that no two electrons occupy the same energy state.

Which of the following is not always a property of lasers? a) All of the photons in a laser light have the same phase b) All laser photons have nearly identical frequencies c) Laser light moves as a beam, spreading out very slowly d) Laser light is always brighter than other sources of light e) Lasers depend on an inverted population of atoms where more atoms occupy a higher energy state than some lower energy state

d) Laser light is intense, but not always brighter than other sources of light Laser light is directional and thus, the light moves as a beam and spreads slowly. Laser is a monochromatic source of light. Photons are in phase and thus the frequencies are nearly identical.

Under what condition(s) can the exact location and velocity of an electron be measured at the same time? a) The electron is in the ground state of the atom b) The electron is in an excited state of the atom c) The electron is free (not bound to an atom) d) Both (a) and (b) e) Never

e) Never Heisenberg's uncertainty principle states that the position and momentum of a microscopic particle cannot be determined simultaneously. If you know the position or the momentum of a particle accurately, we cannot measure these two observables simultaneously to an arbitrary accuracy. If you know one of these quantities accurately, we can measure uncertainly of the other quantity only.