Chem 101 Practice Problems Lectures 1-?

5.88 × 10⁻²⁵ J

A photon has a frequency of 8.87 × 10⁸ Hz. What is the energy of this photon? (h = 6.626 × 10⁻³⁴ J • s)

400nm

A photon of blue light has a frequency of 7.5 × 10¹⁴ Hz. Calculate the wavelength of this photon (c = 3.00 × 10⁸ m/s) in nanometers.

longer

A single bond, compared to a double bond is...

5.13 × 10¹⁴ s⁻¹

Calculate the frequency in hertz of electromagnetic radiation that has a wavelength of 585.0 nm. (c = 3.00 X 10⁸ m/s)

Zr

Consider an atom of zirconium which has a mass number of 96. What is the chemical symbol of this element?

6.39 × 10⁻¹⁹ J

Determine the energy of a photon with a wavelength of 311 nm. (h = 6.626 × 10⁻³⁴ J • s and c = 3.00 × 10⁸ m/s)

D

Energy of a photon is ______ proportional to frequency, and _______ proportional to wavelength. A) directly, directly B) inversely, inversely C) directly, not D) directly, inversely E) inversely, directly

C. 3p

For which atomic orbital does n = 3 and ℓ = 1? A) 2s B) 3s C) 3p D) 3d E) 4d

A. O2

Identify which of the following molecules has a double bond. A) O₂ B) H₂ C) Br₂ D) HF

C

In a covalent bond A) two atoms exchange electrons and the ions are attracted to one another. B) two ions come together and form a crystal lattice. C) two atoms share valence electrons and those shared electrons form the chemical bond. D) two elements react and form a new compound.

B

Light wave A has a greater frequency than light wave B. Which has a greater wavelength? A) Wave A B) Wave B C) They're equal D) Not enough info

C. number of electrons

Neutral atoms of all isotopes of a given element have the same A) number of protons and neutrons B) number of neutrons C) number of electrons D) mass numbers E) masses

B) F > Be > Li > Ba

Rank the following atoms in order of decreasing first ionization energies (i.e., highest to lowest): Li, Be, Ba, F. A) Ba > Li > Be > F B) F > Be > Li > Ba C) Li > Be > F > Ba D) F > Be > Ba > Li E) Ba > F > Be > Li

D. Lower, longer

Red light has a _____ frequency and a _____ wavelength than ultraviolet rays. A. Higher, shorter B. Higher, longer C. Lower, lower D. Lower, longer E. Lower, shorter

B. Valence

Single, double, or triple covalent bonds in a carbon atom are formed from A) inner shell electrons B) valence electrons. C) both inner shell and valence electrons.

Ionic

The compound NaBr is:

electron affinity

The energy released in the reaction F(g) + e⁻ → F⁻(g) is known as the

C. Al

The first five ionization energies of an element are as follows (in kJ/mol): 577.9, 1820, 2750, 11600, 14800. Which of the following elements is most likely to have these ionization energy values? A) Na B) Mg C) Al D) Si E) P

C. Electrons

The net charge on an atom of a given element changes as ______ are added or removed. A) neutrons B) protons C) electrons D) protons and electrons

B. Protons and Neutrons

The nucleus of an atom contains: A) Protons and electrons B) Protons and neutrons C) Electrons and neutrons D) Protons, neutrons and electrons E) Electrons only

5.0 × 10⁻¹⁹ J

The scattering of sunlight by the mixture of gas molecules in air results in the blue color of the sky. Calculate the energy (in Joules) of a single photon of blue light with a frequency of 7.5 × 10¹⁴ Hz. (h = 6.626 × 10⁻³⁴ J • s)

True

True or false: two electrons can simultaneously occupy the same (n,ℓ,mℓ) orbital. A) True B) False

E) total number of protons and neutrons in the atom

What does the mass number of an atom represent? A) number of neutrons in the atom B) number of protons in the atom C) atomic mass of the element D) total number of electrons and neutrons in the atom E) total number of protons and neutrons in the atom

A) Francium (Fr)

What element is theoretically the largest of all on the periodic table? A) Francium (Fr) B) Helium (He) C) Hydrogen (H) D) Lead (Pb) E) Radon (Rn)

Metal

What type of element is Zr?

[Ar]3d⁶

Write the condensed (noble-gas) electron configuration of Fe (2+).

5.72 × 10⁻¹⁸ J

In Einstein's photoelectric experiment, the kinetic energy of an electron displaced from a metal by a photon was the difference between the energy of a photon and a threshold energy value for the metal. If you were to perform a similar experiment with cobalt, which has a threshold energy of 8.01 × 10⁻¹⁹ J, and ultraviolet light of wavelength 30.5 nm, what would be the kinetic energy (in J) of the electron displaced?

2.76 × 10⁻¹⁸ J

In Einstein's photoelectric experiment, the kinetic energy of an electron displaced from a metal by a photon was the difference between the energy of a photon and a threshold energy value for the metal. If you were to perform a similar experiment with the metal copper, which has a threshold energy of 8.17 × 10⁻¹⁹ J, and ultraviolet light of wavelength 55.5 nm, what would be the kinetic energy (in J) of the electron displaced?

1s²2s²2p⁶3s²3p⁶4s²

Write the complete ground-state electron configuration for Ca

B. 38

How many protons are in an atom of strontium-90? A) 2 B) 38 C) 87.62 D) 90

C. B-F

Based on their positions in the periodic table, which of the following bonds is the most polar? A) O - F B) C - F C) B - F D) F - F

D. Groups

Columns on the periodic table are known as A) Periods B) Halogens C) Metals D) Groups E) Metalloids

2.75 m

Calculate the wavelength in meters of electromagnetic radiation that has a frequency of 1.09 × 10⁸ s⁻¹. (c = 3.00 X 10⁸ m/s)

36

Consider an atom of zirconium which has a mass number of 96. How many electrons are in an atom of zirconium with a charge of +4?

56

Consider an atom of zirconium which has a mass number of 96. How many neutrons are in an atom of zirconium with a mass number of 96?

40

Consider an atom of zirconium which has a mass number of 96. How many protons are in an atom of zirconium?

D) the true nuclear charge minus the charge that is shielded by electrons.

Effective nuclear charge, Zeff, is defined as A) the number of protons minus the number of valence electrons. B) the difference in electronegativities of two bonded atoms or ions. C) the number of protons minus the number of electrons. D) the true nuclear charge minus the charge that is shielded by electrons. E) the number of protons in the nucleus.

A) The ejected electrons would have greater kinetic energy.

Photons are shone on a piece of metal and one electron is ejected for each absorbed photon. What happens when the wavelength of light is decreased? A) The ejected electrons would have greater kinetic energy. B) More electrons would be ejected. C) The velocity of the ejected electrons would decrease. D) The ejected electrons would have lower kinetic energy. E) No change in the ejected electrons would be observed.

D. 7A (17)

The halogens are found in Group ____ A) 1A (1) B) 2A (2) C) 6A (16) D) 7A (17) E) 8A (18)

30

What is the atomic number for an element whose mass number is 78, which contains 48 neutrons per atom?

C

Which atom in the C-Cl bond has a partial positive charge (δ⁺)?

1s²2s²2p⁶

Write the complete ground-state electron configuration for Al (3+)

E. 5th

For an atom of carbon, which ionization will exhibit a very large increase in the energy relative to the preceding ionization? A) 1st B) 2nd C) 3rd D) 4th E) 5th

B. Greater than

In the Bohr model of the hydrogen atom, the energy required to excite an electron from n = 2 to n = 3 is _______________ the energy required to excite an electron from n = 3 to n = 4? A) less than B) greater than C) equal to D) equal to or less than E) equal to or greater than

A) Rb > Mg > B > N > F

Rank the following atoms in order of decreasing size (i.e., largest to smallest): Rb, F, Mg, B, N. A) Rb > Mg > B > N > F B) N > F > B > Mg > Rb C) Rb > Mg > F > N > B D) Mg > Rb > B > N > F E) Rb > Mg > N > B > F

D) Rb < Mg < B < N < F

Rank the following atoms in order of increasing first ionization energies (i.e., lowest to highest): Rb, F, Mg, B, N. A) F < N < B < Mg < Rb B) Rb < Mg < F < N < B C) Mg < Rb < F < N < B D) Rb < Mg < B < N < F E) Rb > B > N > F > Mg

D. Energy is reduced by 1/2

What happens to the energy of a photon if the wavelength is doubled? A) Energy doubles B) Energy quadruples C) No change in energy D) Energy is reduced by one-half E) Energy is reduced by one-quarter

41

What is the atomic number for an element whose mass number is 92, which contains 51 neutrons per atom?

4.64 × 10⁻¹⁹ J

What is the energy of a photon with a frequency of 7.01 × 10¹⁴ s⁻¹? (h = 6.626 × 10⁻³⁴ J • s)

1.82 × 10⁻¹⁹ J

What is the energy of light that must be absorbed by a hydrogen atom to transition an electron from n = 3 to n = 6?

1.07 × 10¹⁵ s⁻¹

What is the frequency of a photon if the energy is 7.07 × 10⁻¹⁹ J? (h = 6.626 × 10⁻³⁴ J • s)

5.61 × 10¹⁴ s⁻¹

What is the frequency of green light that has a wavelength of 535 nm? (c = 3.00 x 10⁸ m/s)

138

What is the mass number for an atom of barium containing 56 protons and 82 neutrons?

1

What is the maximum number of electrons that can have the following set of quantum numbers? n = 4, ℓ = 3, mℓ = 3, ms = -½

484nm

What is the wavelength (in nm) of blue light that has a frequency of 6.19 × 10¹⁴ s⁻¹? (c = 3.00 × 10⁸ m/s)

434nm

What is the wavelength of light (in nm) emitted when an electron transitions from n = 5 to n = 2 in a hydrogen atom?

E. Hund's rule

What quantum mechanics principle states that electrons are added to atomic orbitals with the same energy so that each orbital is singularly occupied with electrons having the same spin? A) Schrödinger's equation B) Heisenberg uncertainty principle C) Pauli exclusion principle D) Aufbau principle E) Hund's rule

B. Bohr

What scientist proposed that the electron in a hydrogen atom can only have certain energies (i.e., the electron is quantized)? A) Planck B) Bohr C) Rutherford D) Rydberg E) de Broglie

A.) F

Which atom in the Br-F molecule has a partial negative charge (δ⁻)? A) F B) Br C) Both D) Neither

B. Proton

Which has a greater mass? A) Electron B) Proton C) They have equal masses D) Not enough information

E) The atoms of one element are the same as atoms of another element.

Which is not one of Dalton's hypotheses of atomic theory? A) Elements are composed of atoms. B) Compounds are composed of atoms of more than one element. C) A chemical reaction involves the rearrangement of atoms. D) All atoms of a given element are identical. E) The atoms of one element are the same as atoms of another element.

Li

Which of the following atoms would have the longest de Broglie wavelength, if all have the same velocity? A) Li B) Na C) Fe D) Pb E) Not possible to tell with given information

C) two atoms, one atom which is more electronegative than the other, exchange electrons and the charges hold the atoms together.

Which of the following best describes what happens when an ionic bond forms? A) two atoms come together and share electrons in order to fill their octets. B) two atoms give up their electrons in order to form a bond. C) two atoms, one atom which is more electronegative than the other, exchange electrons and the charges hold the atoms together. D) Two atoms with similar electronegativities exchange electrons and the charges hold the atoms together.

B.) silver

Which of the following is a transition metal? A) Strontium B) Silver C) Sulfur D) Samarium E) Sodium

D) Each successive ionization requires increasing amounts of energy.

Which of the following is true concerning successive ionizations of an atom and its ions? A) Each successive ionization requires less energy to achieve. B) All ionizations require the same amount of energy. C) The amount of energy required to achieve a successive ionization doubles with each electron removed. D) Each successive ionization requires increasing amounts of energy. E) The first two ionizations are endothermic but each ionization afterwards is exothermic.

A) ψ² describes the probability of finding an electron in space.

Which of the following is true concerning ψ²? A) ψ² describes the probability of finding an electron in space. B) ψ² describes the exact path of electron motion in an orbital. C) ψ² describes the electronic structure of the atom according to the Bohr model. D) ψ² describes the exact volume of an atom. E) ψ² describes the size of an atom.

D. 3f

Which of the following orbitals cannot exist? A) 2p B) 3d C) 4d D) 3f E) 162p

D) N³⁻ > F⁻ > Mg²⁺ > Si⁴⁺

Which of the following series of isoelectronic ions (Mg²⁺, N³⁻, F⁻, Si⁴⁺) has the ionic radii in order of largest to smallest? A) Mg²⁺ > N³⁻ > F⁻ > Si⁴⁺ B) Mg²⁺ > Si⁴⁺ > F⁻ > N³⁻ C) N³⁻ > F⁻ > Si⁴⁺ > Mg²⁺ D) N³⁻ > F⁻ > Mg²⁺ > Si⁴⁺ E) F⁻ > N³⁻ > Si⁴⁺ > Mg²⁺

A) Ca²⁺ < K⁺ < Cl⁻ < P³⁻

Which of the following series of isoelectronic ions correctly lists the ions in order of increasing size (i.e., smallest to largest)? A) Ca²⁺ < K⁺ < Cl⁻ < P³⁻ B) K⁺ < Ca²⁺ < P³⁻ < Cl⁻ C) P³⁻ < Cl⁻ < K⁺ < Ca²⁺ D) Cl⁻ < K⁺ < Ca²⁺ < P³⁻ E) K⁺ < Ca²⁺ < Cl⁻ < P³⁻

C) n = 3, ℓ = 1, mℓ = 1

Which of the following sets of quantum numbers can describe a 3p electron? A) n = 1, ℓ = 3, mℓ = 1 B) n = 3, ℓ = 2, mℓ = 1 C) n = 3, ℓ = 1, mℓ = 1 D) n = 3 , ℓ = 0, mℓ = 1 E) n = 2, ℓ = 3, mℓ = 1

A) n = 4, ℓ = 0, mℓ = 0

Which of the following sets of quantum numbers can describe a 4s electron? A) n = 4, ℓ = 0, mℓ = 0 B) n = 3, ℓ = 0, mℓ = 0 C) n = 3, ℓ = 2, mℓ = 0 D) n = 4, ℓ = 1, mℓ = 0 E) n = 3, ℓ = 1, mℓ = 0

B

Which of the following sets of quantum numbers is not allowed? A) n = 1, ℓ = 0, mℓ = 0 B) n = 4, ℓ = 0, mℓ = -1 C) n = 3, ℓ = 1, mℓ = 0 D) n = 2, ℓ = 0, mℓ = 0 E) n = 3, ℓ = 2, mℓ = -2

C) n = 2, ℓ = 2, mℓ = 2

Which of the following sets of quantum numbers is not allowed? A) n = 2, ℓ = 0, mℓ = 0 B) n = 3, ℓ = 2, mℓ = 0 C) n = 2, ℓ = 2, mℓ = 2 D) n = 3, ℓ = 1, mℓ = -1 E) n = 4, ℓ = 2, mℓ = 1

D

Which of the following sets of quantum numbers is not allowed? A) n = 3, ℓ = 2, mℓ = -2 B) n = 4, ℓ = 3, mℓ = -3 C) n = 2, ℓ = 1, mℓ =-1 D) n = 2.5, ℓ = 0, mℓ = 0 E) n = 3, ℓ = 2, mℓ = -1

A. S

Which of the following types of electrons penetrates most toward the nucleus and therefore has the greatest shielding effect? A) s B) p C) d D) f E) all penetrate equally

1s²2s²2p⁶3s²3p⁶

Write the complete ground-state electron configuration for Cl (-)

B. In the same group

Elements that are most similar in their properties are found _____ A) in the same period. B) in the same group. C) have the same electron configurations. D) to occur randomly throughout the table. E) diametrically opposite each other on the periodic table.

C. 2

How many core electrons does an atom of beryllium (Be) contain? A) 0 B) 1 C) 2 D) 3 E) 4

11

How many different types of orbitals are present in the h-subshell?

D. 20

How many electrons are in a neutral ⁴¹Ca atom? A) 2 B) 20 C) 21 D) 41

6

How many electrons are shared between two atoms in a triple bond?

10

How many electrons can be assigned to orbitals designated by the quantum numbers n = 3, ℓ = 2?

10

How many electrons in an atom can have the following quantum numbers? n = 3, ℓ = 2

1

How many electrons in an atom can have the following quantum numbers? n = 4, ℓ = 2, mℓ = -2, ms = +½

6 lines

How many lines would be seen in the hydrogen spectrum if an electron would fall from n = 4 to the ground state?

10 lines

How many lines would be seen in the hydrogen spectrum if an electron would fall from n = 5 to the ground state?

5

How many orbitals are allowed in the subshell when ℓ = 2?

A) 34 p, 36 e

How many protons (p) and electrons (e) are found in a Se²⁻ ion? A) 34 p, 36 e B) 34 p, 32 e C) 32 p, 34 e D) 36 p, 34 e E) 34 p, 34 e

4

How many unpaired electrons are found in a ground state atom of Fe?

2

How many unpaired electrons are found in a ground state atom of O?

B

If light has a lot of energy, it will have: A) A small frequency B) A small wavelength C) Low speed D) High speed E) A small number of photons

1

If n = 2, what is the maximum allowed value for ℓ?

A.) n=6

If ℓ = 0, which of the following may be true? A) n = 6 B) mℓ = -1 C) mℓ = 1 D) ms = 1 E) ms = 0

C. There will be more electrons ejected

In the photoelectric effect, if the intensity of light shone on a metal increases, what will happen? A) Ejected electrons will be faster B) Ejected electrons will be slower C) There will be more electrons ejected D) There will be fewer electrons ejected E) No change

D) O < Be < Li < Al < Ba

Rank the following atoms in order of increasing size (i.e., smallest to largest): Li, Al, Be, Ba, O. A) Li < Al < Be < Ba < O B) Ba < Al < Li < Be < O C) Li < Be < O < Al < Ba D) O < Be < Li < Al < Ba E) O < Li < Be < Ba < Al

E) due to the effective nuclear charge increasing.

The trend towards smaller atomic radii as one moves to the right in a period is _____. A) faulty, as atomic radii in a period are nearly uniform in size. B) because of electron pair repulsion causing the expansion of the orbitals. C) wrong. Atomic radii increase across a period left to right as the larger d and p orbitals are occupied after the s orbital. D) due to the effective nuclear charge decreasing. E) due to the effective nuclear charge increasing.

273

What is the wavelength (in nm) of a photon if the energy is 7.27 × 10⁻¹⁹ J? (h = 6.626 × 10⁻³⁴ J • s)

D. Rydberg

What scientist first developed an equation to calculate the wavelengths of lines in the emission spectrum of hydrogen atoms? A) Planck B) Bohr C) Rutherford D) Rydberg E) de Broglie

C) ²⁸Si and ²⁹Si

Which of the following pairs represent isotopes? A) ²⁸Si and ²⁸Si⁴⁺ B) ²⁸Si and ²⁸Al C) ²⁸Si and ²⁹Si D) ²⁸Si and ²⁸Si⁴⁻ E) ²⁸Si⁴⁺ and ²⁸Al³⁺

C) In³⁺ < In⁺

Which of the following radii comparisons is correct? A) N³⁻ < N B) Ti⁴⁺ > Ti³⁺ C) In³⁺ < In⁺ D) C⁴⁺ > C⁴⁻ E) As³⁻ < As³⁺

C) Pauli exclusion principle

Which of the following states that no two electrons can have the same set of four quantum numbers? A) Hund's rule B) de Broglie wave equation C) Pauli exclusion principle D) Bohr equation E) Schrödinger equation

B. Ionization energy

Which periodic trend quantifies the amount of energy required to remove an electron from a neutral, gaseous atom? A) Atomic Radius B) Ionization Energy C) Ionic Radius D) Electron Affinity E) Electronegativity

D. Both A and B

Which postulate(s) of Dalton's atomic theory of matter is/are NOT true? A) Atoms of a given element are identical B) Atoms are indestructible C) Atoms combine in simple ratios to form compounds D) Both (A) and (B)

C. (3,0,1)

Which quantum state (n,ℓ,mℓ) is NOT possible? A) (2,0,0) B) (3,1,-1) C) (3,0,1) D) (3,2,2) E) (16,15,14)

B. Heisenberg

Which scientist surmised the scientific principle that the position and momentum of an electron cannot be known simultaneously with a high degree of accuracy? A) Planck B) Heisenberg C) Schrödinger D) de Broglie E) Pauli

C) Schrödinger

Who developed the equation that allowed the energy of the electron to be described quantum mechanically? A) Einstein B) Planck C) Schrödinger D) Heisenberg E) de Broglie

1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²4d¹⁰

Write the complete ground-state electron configuration for Cd

1s²2s²2p¹

Write the complete ground-state electron configuration of B

1s²2s²2p⁶3s²3p¹

Write the complete ground-state electron configuration of aluminum.

1s²2s²2p⁶3s²3p⁵

Write the complete ground-state electron configuration of cl

[Ar]4s¹3d⁵

Write the condensed (noble-gas) electron configuration of Chromium

[Ar]3d⁴

Write the condensed (noble-gas) electron configuration of Cr²⁺.

[Ar]3d⁹

Write the condensed (noble-gas) electron configuration of Cu. (2+).

[Ar]3d⁵

Write the condensed (noble-gas) electron configuration of Fe (3+)

[He]2s²2p⁴

Write the condensed (noble-gas) electron configuration of Oxygen.

[Ar]3d²

Write the condensed (noble-gas) electron configuration of Ti²⁺.

[Ar]4s²3d¹⁰4p³

Write the condensed (noble-gas) electron configuration of arsenic

[Xe]6s²

Write the condensed (noble-gas) electron configuration of barium.

[Ar]4s²3d¹⁰4p⁵

Write the condensed (noble-gas) electron configuration of bromine

[Ar]4s¹3d¹⁰

Write the condensed (noble-gas) electron configuration of copper.

[Kr]5s²4d¹⁰5p¹

Write the condensed (noble-gas) electron configuration of indium.

[Kr]5s²4d⁶

Write the condensed (noble-gas) electron configuration of ruthenium

[Ar]4s²3d²

Write the condensed (noble-gas) electron configuration of titanium

[Ar]3d10

Write the condensed (noble-gas) electron configuration of zinc (2+)

[Ar]3d104s2

Write the condensed (noble-gas) electron configuration of zinc.

A) will have more attraction to the electrons in a chemical bond.

A more electronegative atom A) will have more attraction to the electrons in a chemical bond. B) is more likely to lose an electron. C) is less likely to form a chemical bond. D) is more likely to form an ionic bond with another highly electronegative atom.