PHY Chapter 18 Smartbook

The energy of the stable orbits in hydrogen is given by the formula E = E0/n^2 , where E0 = -13.6 eV. The energy level of the second excited state (n = 2) is -_____ eV.

-3.4

X-rays were found to not be subatomic particles, but rather a type of _____ radiation.

electromagnetic

The energy emitted, in the form of light, by an electron jumping from a high-energy orbital to a low-energy orbital depends only on

the difference in energy between the two states.

According to Bohr's model, the centripetal acceleration for an electron orbiting about a nucleus is given by the _____.

electrostatic force

When an electron jumps from one orbit to a lower energy orbit, light is _____ by the atom.

emitted

What was the discovery made by Planck and Einstein?

Light waves sometimes behaves as particles.

What factor(s) influence the spectrum that a blackbody emits?

Temperature

An atom can behave as

a particle. a wave.

Rutherford was able to determine that there were at least _____ distinct types of radiation being emitted from the uranium sample.

three or 3

In quantum mechanics, the orbits of electrons are

three-dimensional standing waves. probability distributions. centered around the nucleus.

Unlike quantum mechanics, de Broglie envisioned the electron waves orbiting the nucleus as standing waves in _____ dimensions.

two

The spectrum of electromagnetic waves produced by any element is _____ to that element.

unique

An electron microscope captures a higher resolution image of a sample by shining electrons on the sample instead of visible light. This is an example of De Broglie's idea that a particle such as the electron can behave like a _____

wave

The probability of finding the electron a certain places is described by the standing _____ for that electron

wave

An atom's atomic spectrum is the set of different _____ produced by an atom when it is excited by some means, such as heat or electricity.

wavelengths or colors

A radical idea proposed by de Broglie was that things traditionally thought of as particles sometimes behaved as _____.

waves

Imagine you had a Bohr atom with five orbits. In order from highest energy to lowest energy they are: A, B, C, D, and E. The orbits have energies that are equally spaced (for instance, the energy from B to A is the same as from C to D). Rank the following jumps of the electron in order from the most energetic light emitted (top) to the smallest energy emitted.

1. A to E 2. B to E 3. B to D 4. A to B

When Rutherford placed the natural radiation beam, into a magnetic field it separated into three beams. The beams were deflected by different amounts. Rank how much each ray was deflected with the most deflection at the top and the least deflection at the bottom.

1. Beta rays 2. Alpha rays 3. Gamma rays

Rank the following objects by their de Broglie wavelength with the smallest wavelength at the top.

1. The Earth traveling around the sun at about 100,000 km/h 2. A truck traveling at 100 km/h 3. A ping-pong ball traveling at 100 m/s 4. An oxygen molecule at room temperature (about 482 m/s)

Rank the following emissions from the cathode-ray tube by their penetrating power, with the highest penetration power at the top.

1. X-rays 2. Cathode ray

The energy of the stable orbits in hydrogen is given by the formula E = E0/n^2 , where E0 = -13.6 eV. The energy level of the second excited state (n = 3) is -_____ eV.

1.5

If a reaction starts with 10 grams of reactants, then there will be _____ grams of products and reactants after the reaction.

10

Drag and drop the amounts of oxygen (in the right column) needed for the reactions against the corresponding reactants and the products (in the left column) so that almost no reactants remain. The atomic weight of oxygen is 16, carbon is 12, zinc is 65, and silicon is 28.

10 grams of zinc to make ZnO - 40.6 grams of oxygen 10 grams of silicon to make SiO2 - 8.8 grams of oxygen 10 grams of carbon to make CO2 - 3.8 grams of oxygen

Match the following reactants and the products (in the left column) with the amounts of oxygen (in the right column) needed for the reactions so that almost no reactants remain. The atomic weight of oxygen is 16, carbon is 12, zinc is 65, and silicon is 28.

10 grams of zinc to make ZnO = 40.6 grams of oxygen 10 grams of silicon to make SiO2 = 8.8 grams of oxygen 10 grams of carbon to make CO2 = 3.8 grams of oxygen

The mass of oxygen (atomic weight 16) needed to completely react with 10 grams of hydrogen (atomic weight 1) to form hydrogen peroxide, H2O2, is _____ grams of oxygen.

160

The atomic spectrum of hydrogen has just _____ visible lines.

4 or four

Which of the following are possible values for the angular momentum of an electron in Bohr's new model of the atom?

5h/π h/2π

At a given frequency of light, f, which energies are allowed? The variable h is Planck's constant.

5hf 42hf

Which of the following statements are true.

A blackbody's spectrum depends on its temperature. A blackbody's spectrum is continuous.

Match the following spectra with its source.

A discrete spectrum = An element A continuous spectrum = A blackbody

Which of the following statements are true of a molecule? (Check all that apply.)

A molecule can be a combination of atoms of a same element. A molecule can be a combination of atoms of different elements.

Imagine you had a Bohr atom with five orbits. In order from highest energy to lowest energy they are: A, B, C, D, and E. The orbits have energies that are equally spaced (for instance, the energy from B to A is the same as from C to D). Match which jumps would emit the same wavelength of light (amount of energy).

A to C - B to D B to E - A to D C to D - A to B

Which of the following statements is true about the Heisenberg uncertainty principle?

An extended wave, which permits accurate definition of the wavelength, gives us no precise information regarding position.

Which of the following are features of Bohr's model of the atom?

Angular momentum is quantized The energy of the orbit is quantized The electron orbits the nucleus

Which of the following statements are true for a cathode ray tube? (Check all that apply.)

As air is pumped out of the tube, a colorful glow first appears in the gas near the cathode. A dark region starts to form near the cathode and then moves across the tube toward the anode as the pressure is further reduced.

When Rutherford used alpha particles to probe the material, he found the following results: most of the alpha particles went through the atom with only minor scattering, but some of the alpha particles were deflected completely around. What conclusions are supported by these ideas?

Atoms are largely empty space. Atoms have a lot of their positive charges in one location. Atoms have a very small, very dense region. Atoms have their negative charge distributed over their volume.

Which of the follow are components of natural radiation emitted by uranium as discovered by Rutherford?

Beta rays Alpha rays Gamma rays

An electron has a mass of _____ × 10^-31 kg and a charge of _____ × 10^-19 C.

Blank 1: 9.1 Blank 2: -1.6

J. J. Thomson used electric and magnetic fields to measure the ratio of the electron's _____ and _____.

Blank 1: charge Blank 2: mass

When different atoms or molecules interact to form new molecules, it is called a(n) _____ _____.

Blank 1: chemical Blank 2: reaction

Rutherford distinguished the _____ different types of natural radiation being emitted by uranium by passing the particles though a _____ field and seeing how they were deflected.

Blank 1: three Blank 2: magnetic

What was the question that de Broglie asked that lead to the development of quantum mechanics?

Can particles behave like waves?

Match the following phenomenon from the cathode-ray tube to the type of object it is.

Cathode ray = Subatomic particle now called the electron X-ray = Electromagnetic radiation of very short wavelength

Which types of particles or radiation are generated by a cathode-ray tube?

Electrons X-rays

Match the constituent of the atom with a major property it causes.

Electrons = Responsible for the size of the atoms Nucleus = Responsible for most of the mass of the atoms

Identify the true statements about elements after the systematic study.

Elements mixed together could be heated to form a new substance. Elements ground up together could always be separated out to retrieve the original elements.

Which of the following are discrete?

Energy Element's spectrum

Which of the following statements are false about the electrons having different quantum numbers?

Every electron in an atom must have the same quantum numbers. Two electrons can have the same quantum numbers.

True or false: An ideal particle has a definite volume and some extension in space.

False

True or false: In a chemical reaction, the atoms of elements combine in different ways and the fundamental nature of the atoms change.

False

True or false: X-rays are a form of electromagnetic waves with very long wavelengths and low frequencies.

False

Which of the following factors influence the glow of a cathode ray? (Check all that apply.)

Gas pressure Type of gas

Match each thing on the left to it's characteristic on the right.

Ideal wave - Extends indefinitely in space Ideal particle - A simple point in space Real wave - Has some finite length in space Real particle - Has some extension in space

What was the thing about natural radiation that physicists found puzzling?

It did not require an outside source of energy.

Which of the following statements are true of natural radioactivity? (Check all that apply.)

It does not require any special preparation process. It is produced continuously by compounds containing uranium or thorium. It does not require any apparent source of energy to produce radiation.

Bohr's model of the atoms was made in order to account for many different discoveries. What discoveries did he combine into one new model of the atom?

Regularities in the hydrogen spectrum Light emission and absorption being only in discrete chunks Knowledge of the atom's nucleus The existence of the electron

What was needed in order for one of Antoine-Henri Becquerel's (uranium- or thorium-containing) phosphorescent materials to cause a photographic plate to be developed?

Nothing needed to be done to the sample

Which of the following are present in atoms?

Nucleus Electrons

Match the following atomic constituents with their properties.

Nucleus - Very dense and positively charged Electrons - Very light and negatively charged

Pick out the visible colors in the hydrogen spectrum.

One red line One blue line Two violet lines

What were the assumptions and visualizations made by de Broglie to explain why certain orbits are stable? (Check all that apply.)

Particle have wavelike properties. He visualized a standing particle wave around a circular orbit.

You observe an experiment that starts with some reactants and ends with a puff of smoke. The reactants have a mass of 10 grams while the charred remains on the table have a mass of 5 grams. Which of the following conclusions are correct?

Some of the reactant was transformed from solid to gas. Five grams escaped into the air.

When Rutherford placed the beam of natural radiation from the sample of uranium in a magnetic field, he found that some of the particles were deflected a little bit off to one side (alpha rays), some were deflected a lot to the other side (beta rays), and some were completely undeflected by the magnetic field (gamma rays). Which of the following conclusions are correct?

The alpha ray particles must have the opposite charge as the beta ray particles. The gamma ray particles must be uncharged. The alpha ray particles must have a lower charge to mass ratio than the beta ray particles.

Which of the following lines of evidence supported the hypothesis that the cathode-ray was a subatomic particle?

The cathode-ray particle behaved identically regardless of the metal used to make it. The mass of the cathode-ray particle was nearly 2000 times less than that of hydrogen. All cathode-ray particles had the same mass to charge ratio.

In Bohr's new model of the atom, he had to assume something that was different from what classical physics predicts. Which of the following statement is the correct assumption?

The electrons had stable orbits in which they did not radiate energy.

Which of the following statements depict the similarities between an atom and the solar system.

The majority of the mass is located in a central object. The attractive force which holds the system together follows an inverse square law. The central object is tiny compared to the size of the system.

When a fast, dense projectile is fired at an object, though a few bounce back toward the shooter, most of the projectiles go straight through. What conclusion can we draw?

The object must have something as dense or denser than the projectile.

What does the standing wave for an electron describe?

The probability of finding the electron at some spot. The probability of finding the electron in some orientation.

When a magnetic field is applied to a cathode ray, the ray is _____.

deflected

After gathering 12 kg of firewood and burning it all afternoon, you decide to weigh the ashes. You find that the ashes weigh 1.1 kg. Which of the following is the correct conclusion about this process?

The rest of the firewood was transformed into the gas phase.

How are scientists able to tell what elements make up distant stars?

The spectrum from each element is unique to that element.

What was needed in order for a phosphorescent material to be able to expose a photographic plate?

Thorium Uranium

True or false: The main difficulty with de Broglie's idea of a standing wave on a circular orbit is that the circular orbit is two-dimensional and the atom itself is three-dimensional.

True

Roentgen placed a cover on the cathode-ray tube and still found that there was a beam of particles, which he called _____ rays, emerging from the cathode-ray tube.

X

In what ways do cathode-rays and X rays differ?

X rays can penetrate a cover over the cathode-ray tube. Cathode-rays are confined to the cathode-ray tube. Cathode-rays could not travel far in air.

To change the spectrum of the light emitted by a blackbody, one would have to change its _____.

temperature or temp

When an electron jumps from one orbit to a higher-energy orbit, light is _____ by the atom.

absorbed

In the periodic table illustrated by Mendeleev, the elements are arranged in the increasing order of their _____.

atomic weight

Continually grinding a substance into finer and finer powder begs the following question. Can the particles that make up the substance always be made smaller? Some early speculation was that eventually you would reach a point where the substance was made of particles of such small size they could not be subdivided again. These particles were called _____ , which in Greek means indivisible.

atoms

Regardless of the metal used for the cathode, the cathode-ray particles all have the same _____ to mass ratio, suggesting they were the same particle and a constituent of all atoms.

charge

Elements in the same family (column) on the periodic table have the same or similar

chemical properties. atomic proportions with other elements.

When combining substances to make a chemical reaction, a specific proportion is needed in order for them to react _____.

completely

The cathode ray particle was found to be lighter than hydrogen (the lightest element) and inside of every element. It was also found that these particles had a negative charge. Today we call these particles _____.

electrons

The problem with the planetary model of the atom was that it should be constantly losing _____ due to the electromagnetic waves emitted by the orbiting electron.

energy

The Coulomb force between charged particles is inversely proportional to the square of the distance between them. In the solar system, the planets are held in orbit about the sun by the force of _____ , which is proportional to the inverse square of the distance between the planets and the sun. This similarity led people to picture early models of the atoms as miniature solar systems.

gravity

To produce an atomic spectrum pattern, an element must

have its emitted light separated through a prism. be heated to high temperatures.

Alpha rays, made up of alpha particles, were discovered by Royds and Rutherford to be

helium atoms stripped of their electrons.

After trapping the alpha particles from the decay of radium in a tube that had electrodes, across which a high voltage was introduced, Rutherford and Royds were able to detect that the alpha particles were the element _____.

helium or He

J. J. Thomson was surprised to find that the cathode-ray particle was around 2000 times lighter than _____ , the lightest element. This suggested it could be a piece of an atom.

hydrogen

The de Broglie hypothesis was that the momentum of the particle was _____ proportional to the wavelength of the particle.

inversely

By knowing the velocity and the extent of deflection produced by the magnetic field, Thomson could estimate the _____ of the particles.

mass

Atoms are the smallest building blocks of elements. When different types of atoms are combined (by a chemical reaction), they form _____.

molecules

The Heisenberg uncertainty principle says that the particle's _____ and _____ cannot be known to arbitrary precision simultaneously.

momentum position

When placed in a magnetic field, the cathode ray particle is deflected in a way that is consistent with a _____ charged particle.

negatively

At the center of the atom lies the very dense positively charged _____ , while the electrons, with their negative charge, are arranged much farther out.

nucleus

In most experiments, light acted as if it was a wave. De Broglie's idea was inspired by the knowledge that light could behave as _____ in some experiments.

particles

Unlike the solar system model of the atom, quantum mechanics represents the electron as a _____ distribution.

probability

Planck discovered that the energy from a blackbody could only be emitted in _____ of energy.

quanta discrete chunks

It is possible to identify any element by heating it and looking at its atomic _____ , which is unique for every element. This is often called an element's chemical fingerprint.

spectrum, spectra, or spectrums

De Broglie used his idea of particles behaving as waves to explain the stable orbits of the Bohr model. De Broglie pictured the electron as a _____ wave moving around the nucleus, meaning only complete waves would be stable.

standing