Module 4 Quizzes and HW

What was Niels Bohr's explanation for the observation of atomic spectra? -Electrons could only move in discrete energy steps within an atom. -Nucleons could be excited by different electron energies. -Electrons could not move in an atom. -Any photon could excite an electron. -Only certain photons with the correct energy could excite the quanta in the nucleus.

-Electrons could only move in discrete energy steps within an atom.

What is a probability cloud? -It is a map of the likelihood of a photon ejecting an electron from an atom. -It is a map of the likelihood of finding a particular proton within the nucleus. -It is a map of the likelihood of finding an electron within the nucleus. -It is a map of the likelihood of finding an electron within a given area. -None of the answers are correct.

-It is a map of the likelihood of finding an electron within a given area.

How many electrons can reside in a single atomic orbital?

2

If an element has 15 protons and 16 neutrons and 15 electrons, what is the mass number of the element? 16 None of the answers are correct. 31 15 30

31

A class of students takes an exam and every student scores 80%. What is the class average? Would the class average be slightly less, the same, or slightly more if one of the students instead scored 100%? How is the similar to how we derived the atomic masses of elements?

80% class average slightly more weighted average based on the percent abundance of different isotopes

An element found in another galaxy exists as two isotopes. If 80.0 percent of the atoms have an atomic mass of 80.00 amu and the other 20.0 percent have an atomic mass of 82.00 amu, what is the atomic mass of the element? 80.4 amu 16.4 amu 81.0 amu 81.6 amu 64.0 amu

80.4 amu

Which of the following statements about electrons is true? Electrons behave like waves. Electrons have a negative charge. Electrons are particles. Electrons in atoms can be excited by light energy. All of the answers are correct.

All of the answers are correct.

Which of the following atoms is the largest? Mg Ba Sr Be Ca

Ba

Which color of light comes from the higher energy transition, red or blue? Red is a higher frequency and therefore corresponds to a higher energy level transition. Blue is a higher frequency and therefore corresponds to a lower energy level transition. Blue is a higher frequency and therefore corresponds to a higher energy level transition. Red is a higher frequency and therefore corresponds to a lower energy level transition

Blue is a higher frequency and therefore corresponds to a higher energy level transition.

What role does atomic number play in the periodic table?

Elements are listed in the periodic table in order of icreasing atomic number

Visible light has a frequency range between 7 × 1014 Hz and 4 × 1014 Hz. Which frequency of light would have the most energy? 7 × 1014 Hz Both have same energy. None of the answers are correct. Energy is related to wavelength only, not frequency. 4 × 1014 Hz

Energy is related to wavelength only, not frequency.

Consider these atoms: Helium, Aluminum, and Argon. Rank them from smallest to largest a) in order of size and b) in order of protons

Helium<Argon<Aluminum # of protons: Helium<Aluminum<Argon

Which of the following does not describe a neutron? It is often associated with protons. It has a positive charge equivalent but opposite of an electron's. It is more difficult to detect than a proton or an electron. It is much more massive than an electron.It is a nucleon.

It has a positive charge equivalent but opposite of an electron's.

Which of the following determined the ratio of the charge of an electron to its mass? E. Rutherford's gold foil experiments Avogadro's number experiments Franklin's kite experiments J.J. Thompson's cathode ray deflection experiments

J.J. Thompson's cathode ray deflection experiments

Evidence for the existence of neutrons did not come until many years after the discoveries of the electron and the proton. Give a possible explanation. The neutron lacks an electrical charge. The discovery required the use of ultrafast computers. The neutron is nearly massless. The neutron is only slightly more massive than the proton.

The neutron lacks an electrical charge.

Evidence for the existence of neutrons did not come until many years after the discoveries of the electron and the proton. Give a possible explanation. The neutron lacks an electrical charge. The neutron is only slightly more massive than the proton. The discovery required the use of ultrafast computers. The neutron is nearly massless.

The neutron lacks an electrical charge.

What do the electron configurations for all the group 18 noble gases have in common? They have the same number of electrons. Their outermost occupied shells are filled to capacity. All of the answers are correct. They occupy the same number of shells.

Their outermost occupied shells are filled to capacity.

What did Thompson discover about the electron?

Thomson discovered the electron by experimenting with a cathode ray, tube. He demonstrated that cathode rays were negatively charged. (like charges repel) when a magnet was placed over the tube.

You cannot make a physical model of the atom because... -This statement is false, we can make physical models of the atom. -We don't yet understand the main components of the atom. -Physical models only work for things that are very large. -We cannot actually see atoms.

We cannot actually see atoms.

From which of the following atoms would removing an electron be the most difficult? Xe Rb I Cd Sr

Xe

Does it make sense to say that a textbook is about 99.9 percent empty space? No. Only gases are considered to be 99.9 percent empty space. Liquids and solids are not. No. A textbook could only be considered to be 99.9 percent empty space if it were combusted. No. A textbook is a solid and thus is quite dense. Therefore it is not 99.9 percent empty space. Yes. A textbook like all material things is made up of atoms, which are considered to be 99.9 percent empty space.

Yes. A textbook like all material things is made up of atoms, which are considered to be 99.9 percent empty space.

How would you describe light generated by heating pure elements if it was observed through a prism or spectroscope? Light is absorbed by heated elements so you would not see anything. You would see one line of emitted light, but it would be different for each element. None of the answers are correct. You would see a series of very sharp lines of emitted light. You would see a rainbow of colors.

You would see a series of very sharp lines of emitted light.

The element bromine, Br, has two major isotopes of similar abundance both around 50%. The atomic mass of bromin is reported in the periodic table as 79.904 amu. Choose the most likely set of mas numbers for these 2 bromine isotopes

a) 80Br, 81Br b) 79Br, 80Br c) 79Br, 81Br

If an atom has 43 electrons, 56 neutrons, and 43 protons, what is its approximate atomic mass? What is the name of this element? atomic mass, 137 amu; Barium atomic mass, 99 amu; Technetium atomic mass, 99 amu; Radon atomic mass 142 amu; Einsteinium

atomic mass, 99 amu; Technetium

What did Rutherford discover about the atom?

atomic nucleus

Distinguish between atomic number and mass number

atomic number- # of protons in an element mass number- the sum of protons and neutrons in an element

Which of the above has the most energy? a d b c e

c

Which of the following is not a property of an electron? has a negative charge fundamental component of atoms weighs approximately 9.1 × 10-31 kg charge changes depending on mass

charge changes depending on mass

Who first proposed that electrons exhibit the properties of a wave?

de Broglie?

What was Planck's quantum hypothesis

hypothesized that light energy is quantized- consists of some whole # of fundamental units

An atomic orbital ________. can hold up to four electrons is a region of space is the path of an electron is always spherical

is a region of space

What does a spectroscope do to the light coming from an atom?

it separates the light into color components whose frequencies can then be measured

Neon, Ne, (number 10) has a relatively large effective nuclear charge, yet it cannot attract any additional electrons because ________. of the repulsion of neighboring electrons the outermost shell has gotten too small the outermost shell is too far away from the nucleus its outermost shell is already filled to capacity

its outermost shell is already filled to capacity

Which experiences a greater effective nuclear charge, an electron in the outer shell of neon (atomic number 10) or an electron in the outer shell of sodium (atomic number 11)? sodium because it contains a greater number of shells neon because of less inner shell shielding neon because it is a smaller atom sodium because it contains more protons

neon because of less inner shell shielding

Why do we say atomic spectra are like fingerprints of the elements?

the atoms of each element emit only select frequencies of light. The pattern of these frequencies is unique to that element.

Why is a cathode ray deflected by a nearby electric charge or magnet?

the cathode rays gets deflected towards the positively charged plate because of the fact that cathode rays are negatively charged.

The mass number of an element is ________. the sum of the electrons and the neutrons the sum of the protons and the neutrons the sum of the electrons and the protons the sum of the isotopes the number of protons

the sum of the protons and the neutrons

Thousands of magnetic marbles are thrown into a vertically oriented wind tunnel. As they are thrown, no marbles are free from other marbles. Instead, they clump together in groups of varying numbers. The wind tunnel operator is able to control the upward force of the wind so as to make clumps of marbles hover. She records the various forces of wind required to maintain hovering clumps in units of ounces: 45, 30, 60, 75, 105, 35, 80, 55, 90, 20, 65. From this data, what might be the weight of a single magnetic marble? What is the force of the wind analogous to within Millikan's experiment? A) 3 ounces; the force of the wind is analogous to the force of gravity within Millikan's experiment. B) 5 ounces; the force of the wind is analogous to the strength of the electric field within Millikan's experiment. C) 5 ounces; the force of the wind is analogous to the force of gravity within Millikan's experiment. D) 3 ounces; the force of the wind is analogous to the strength of the electric field within Millikan's experiment.

B) 5 ounces; the force of the wind is analogous to the strength of the electric field within Millikan's experiment.

What is the main difference between a conceptual model and a physical model? A) A physical model represents the shape and form while a conceptual model describes how a system behaves. B) A conceptual model represents the shape and form while a physical model describes how a system behaves. C) Physical models can only be used to represent the real world. D) Conceptual models can only be used to describe concepts. E) Physical models and conceptual models can be used to describe the same things.

B) A conceptual model represents the shape and form while a physical model describes how a system behaves.

Which of the following atoms is the largest? Ba He N Al Cs

Cs

What did Millikan discover about the electron?

Oil Drop experiment: discovered the fundamental increment of all electric charge to be 1.60x10^-19 coulombs

Which contributes more to an atom's mass: electrons or protons? Which contributes more to an atom's size? Protons contribute more to an atom's mass while electrons contribute more to its size. Electrons contribute more to both the mass and size of an atom. Electrons contribute more to an atom's mass while protons contribute more to its size. Protons contribute more to both the mass and size of an atom.

Protons contribute more to an atom's mass while electrons contribute more to its size.

Which of these shows light waves in order of increasing energy? Ultraviolet < Visible < Infrared < Microwave < Radio Visible < Ultraviolet < Microwave < Infrared < Radio Radio < Microwave < Infrared < Ultraviolet < Visible Radio < Microwave < Infrared < Visible < Ultraviolet

Radio < Microwave < Infrared < Visible < Ultraviolet