Chapter 7 review B

The half-life of carbon 14 is 5730 years. If a 1-gram sample of old carbon is 1/8 as radioactive as 1-gram of a current sample, then the age of the old sample is about

17,200 years.

Which of the following isotopes is radioactive?

Carbon-14

The ratio of the energy of a photon to its frequency is

Planck's constant

A nucleon is either

a proton or neutron

Fusing two iron nuclei yields a net

absorption of energy

A new theory conforms to the correspondence principle when it

accounts for verified results of the old theory.

Which experiences the greatest electrical force in an electric field?

alpha particle

A radiation detector measures the radioactivity of a piece of radium by catching and counting alpha particles it emits. According to quantum physics, making this measurement affects the

alpha particles that are caught.

Quantum uncertainties are most predominant for simultaneously measuring the speed and location of

an electron

An atom with an imbalance of electrons to protons is

an ion.

Most alpha particles fired at a gold foil pass through undeflected because the

atoms of gold, like any others, are mostly empty space.

When an alpha particle is ejected from a nucleus, the nucleus then has less

both (mass and charge)

Which body is heated in its interior by nuclear processes?

both (the earth and the sun?)

A beam of electrons has

both of these (particle and wave properties)

Energy released by the sun results from the process wherein atomic nuclei

combine

In both fission and fusion, mass

converts to kinetic energy

The origin of cosmic rays is the

cosmos

In the fissioning of uranium, a chain reaction is caused by

ejected neutrons.

Heavy atoms are not appreciably larger in size than light atoms because the nuclei of heavy atoms have more

electric charge

Once an alpha particle is outside the nucleus it is

electrostatically repelled

Two photons have the same wavelength. They also have the same

frequency and energy

Which radiation has no electric charge associated with it?

gamma rays

Plutonium is not found in any appreciable amounts in natural ore deposits because it

has a short half-life

The electrical force between an inner electron and the nucleus of an atom is larger for atoms of

high atomic number.

X-rays may be regarded as

high frequency radio waves

The most abundant element in the universe is

hydrogen

When a lump of uranium is broken into smaller pieces, the total surface area of the lump

increases

A nucleon has the least mass in the nucleus of

iron

Uranium-235, uranium-238 and uranium-239 are different

isotopes

Compared to the mass of a uranium nucleus before splitting, the pieces it splits into have

less mass

Which of the following are conserved when a photon collides with an electron?

momentum and energy

Different isotopes of an element have different numbers of

neutrons.

A quantum of light is called a

none of these

The half-life on an isotope is one day. At the end of three days, how much of the isotope remains?

one-eighth

A nucleon has more mass when it is

outside the nucleus

The photoelectric effect best demonstrates the

particle nature of light.

Electric forces within an atomic nucleus tend to

push it apart

The source of the Earth's natural heat is

radioactive decay in the Earth's core

Two beams of light, a red beam and a blue beam, have the same energy. The beam with the greater number of photons is the

red beam.

Fusing two helium nuclei yields a net

release of energy

Compared to the wavelengths of visible light, the wavelengths of matter waves are relatively

small

When a beta particle is ejected from a nucleus, the nucleus then has slightly

smaller mass and significantly greater charge

The quantum-mechanical probability cloud for the electron in the hydrogen atom has an average radius

that agrees with the orbital radius of Bohr.

An electron and a proton are traveling at the same speed. Which has the longer wavelength?

the electron

Most of the radioactivity we personally encounter comes from

the natural environment

When a clean surface of potassium metal is exposed to blue light, electrons are emitted. If the intensity of the blue light is increased, which of the following will also increase?

the number of electrons ejected per second

Orbital electrons do not spiral into the nucleus because of

the wave nature of the electron.

Light behaves primarily as a wave when it

travels from one place to another

Which of the following photons has the greatest energy?

ultraviolet

Quantization of electron energy states in an atom is better understood in terms of the electron's

wave nature.