study set 1-9

In an atom, what is the maximum number of electrons that can have the quantum numbers n = 5?

50

Calculate the energy of the n = 3 orbit of the H atom in joules per atom.

2.42 × 10-19 J·atom-1

Which of the following is FALSE?

Avogadro's number, 6.022 × 1023, is an exact number.

Calculate the energy of the n = 3 orbit of the H atom in kilo joules per mole.

-1.46 × 102 kJ·mol-1

Which of the following electron transitions will result in a photon being emitted (select all that apply)?

-1.46 × 102 kJ·mol-1

Calculate the energy (in J) of the electron when it is in the n = 2 level in the Be3+ ion.

-8.712 × 10-18 J

Calculate the frequency of a water wave if the distance between wave crests is 10 m and it travels at a speed of 2 m·s-1.

0.2 Hz

How many moles of atoms are there in a 35.58 g sample of a metal whose molar mass is 91.22 g? Give your answer to 4 significant figures.

0.3900 mol

The average atomic mass of an element is known to be 24.305 amu. Determine the fractional abundance of the isotopes whose fractions are not displayed in the table.

0.8, 0.1

The average atomic mass of an element is known to be 174.967 amu. Determine the fractional abundance of the isotope whose fraction is not displayed in the table.

0.974

Which wavelength of light has the highest frequency?

1 nm

A laser pulse with wavelength of 532 nm contains 3.85 mJ of energy. How many photons are in the laser pulse?

1.03 × 1016 photons

Calculate the frequency of the photon emitted when an electron goes from n = 3 to n = 1 in the He+ ion.

1.17 × 1016 Hz

Calculate the deBroglie wavelength in meters of an electron with a mass of 9.11 × 10-31 kg that has a speed of 5.98 × 105 m·s-1.

1.22 × 10-9 m

What is the wavelength in of microwaves with a frequency of 2.0 × 1010 Hz?

1.5 cm

Calculate the kinetic energy in J of a proton with a mass of 1.67 × 10-27 kg, if it has a deBroglie wavelength of 6.47 × 10-14 m.

1.52 × 10-18 J

Which of the following has the largest mass?

10.0 moles of K

What is the mass in grams of 1.13 ×1024 arsenic (As) atoms?

141 g

Which of these is an incorrect orbital designation?

1p

An instrument can detect 671 photons of light of wavelength of 6.51 × 10-4 m. What is the minimum of amount of energy in J to which the instrument is sensitive?

2.05 × 10-19 J

The energy for one state of the Li2+ ion is -2.18 × 10-18 J. What frequency of light would need to be absorbed to reach a state with an energy of -7.84 × 10-19 J?

2.11 × 1015 Hz

Calculate the following with the correct number of significant figures. (1.428 + 1.08) / 0.288 + (2.83 x 0.360) =

2.2

A single photon in the far infrared region of the electromagnetic spectrum has an energy of 6.95 × 10-22 J. Calculate the wavelength in μm of the photon.

2.86 × 102 μm

The average atomic mass of an element is known to be 24.30 amu. Determine the atomic mass of the isotope whose atomic mass is not displayed in the table. Give your answer to 3 significant figures.

24.9 amu

A sample of a chemical compound contained 1.754 g of the element P and 2.265 g of the element O. Use this information to determine the ratio of the number of moles of P atoms to the number of moles of O atoms.

2:5

Which of these is an incorrect orbital designation?

2d

What is the total number of atoms in a 0.5300 mol sample of a metal that has a mass of 118.2 g? Give your answer to 4 significant figures.

3.192 × 1023 atoms

A 0.22-caliber handgun fires a 27 g bullet at a velocity of 765 m·s-1. Calculate the deBroglies wavelength of the bullet.

3.2 × 10-35 m

The two major isotopes of bromine are 79Br and 81Br. Assume that the masses of the 79Br and 81Br isotopes are 79.00 amu and 81.00 amu, respectively. The average atomic mass of bromine is 79.90 amu. What are the relative % abundances of each isotope? (See whether you can estimate without detailed calculations!)

55.0% 79Br and 45.0% 81Br

What is the frequency of an infrared light that emits 24.5 kJ/mol of energy?

6.14 × 10^13 Hz

What is the wavelength in picometer of gamma ray radiation with a frequency of 4.81 × 1019 Hz?

6.23 pm

The red color emitted by highway safety flares when they are burned is due to salts of strontium ions in their excited states. If strontium ions emit light with energy of 3.12 × 10-19 J per photon when they are excited, calculate the wavelength (in nm) of the emission.

637 nm

How many f orbitals are there?

7

How many gold (Au) atoms are there in 2860 g of gold? Give your answer to 3 significant figures.

8.74 × 1024 atoms

A Li2+ ion absorbs a photon with a wavelength of 2.09 × 102 nm. Calculate the energy difference in J between the initial and final state of Li2+ ion.

9.50 × 10-19 J

What is the relationship between frequency and wavelength?

Frequency is inversely proportional to wavelength.

Which kind of electromagnetic radiation has the shortest wavelength?

Gamma rays

Two stable isotopes of an element have isotopic masses of 10.0129 amu and 11.0093 amu. The atomic mass is 10.81 amu. Which isotope is more abundant?

The isotope with a mass of 11.0093 amu is more abundant.

According to wave theory, which of the following is NOT a description of a wave?

They have measurable mass.

As the electron in a hydrogen atom jumps from the n = 3 orbit to the n = 7 orbit, it

absorbs energy.

An electron in a hydrogen atom undergoes a transition from n = 3 to n = 1. Does this correspond to absorption or emission of energy? What is the sign for the change in energy?

emission, -

The following set of quantum numbers is not allowed: n = 3, l = 0, ml = -2. Assuming that the n and ml values are correct, change the l value to an allowable combination.

l = 2

Which set of three quantum numbers does not specify an orbital in a hydrogen atom?

n = 3; l = 3; ml = -2

Which electron transition in the hydrogen atom results in the emission of light of the longest wavelength? Try to estimate without detailed calculations. (Hint: In the picture of the energy levels (Slide 6 in the Lecture 5 notes), notice that the energy levels of each orbit get closer as we move away from the nucleus. Also, energy is emitted when an electron transitions from a higher energy level to a lower energy level and energy is absorbed when an electron transitions from a lower energy level to a higher energy level.)

n = 4 to n = 3

Which of these is a correct set of quantum numbers to describe a 4p orbital?

n = 4; l = 1; ml = +1

Which of these is a correct set of quantum numbers to describe a 5f orbitals?

n = 5, l = 3, ml = +2

Which of the following determines the identity of an atom?

number of protons

The electromagnetic radiation emitted by an excited-state H atom as it returns to the ground-state depends on

the value corresponding to the differences in energies between nfinal and ninitial.

The amplitude of a wave describes

the difference in height of the highest or lowest points on the wave and its midline.