Chapter 16

At the end of the p-p chain of nuclear fusion in the Sun, hydrogen nuclei have been converted into:

A helium nucleus

According to the formula E=mc2,

A little bit of mass can be converted into a substantial amount of energy

Which of the following particles has the lowest mass?

A neutrino

Which of the following, produced at the core of the Sun, will take the shortest time to emerge from the Sun's photosphere (surface)?

A neutrino

When great currents of hot material rise inside the Sun (and cooler material sinks downward), energy is being transferred by a process known as:

Convection

In the Sun, when a positron and an electron collide, they will produce:

Energy in the form of a gamma ray

What happens to the positron created during the p-p chain of nuclear reactions inside the Sun?

It quickly collides with an electron and turns into gamma-ray energy

Today we realize that the source of energy for the Sun is a process called:

Nuclear fusion

The Sun is an enormous ball of gas. Left to itself, a ball of so many atoms should collapse under its own tremendous gravity. Why is our Sun not collapsing?

Nuclear fusion in the core keeps the temperature and the pressure inside the Sun at a high enough level so that gravity is balanced

The antimatter version of an electron is called a:

Positron

Which of the following is NOT one of the fundamental particles that we find inside atoms?

Positrons

When energy is first produced by fusion deep in the core of the star, that energy moves outward mostly by what process?

Radiation

Which of the following best describes the first set of experiments, using chlorine traps, that were searching for electron neutrinos from the Sun?

The chlorine experiments found only about 1/3 the number of electron neutrinos arriving from the Sun that our models predicted should be coming

Which part of the Sun has the greatest density?

The core

The strongest force we know is:

The nuclear force which holds nuclei together

When did scientist begin to understand how the Sun produces all the energy that it does?

The process was not well understood until the 1930's

In the formula E=mc2, the letter c stands for:

The speed of light

Astronomers and physicists now believe they know what is happening to the missing neutrinos from the Sun (the neutrinos that our theories say should be emerging from the Sun, but our experiments in that underground mine could not find). These neutrinos are:

Turning into a different type of neutrino in a neutrino oscillation

The process of fusion that keeps our Sun shining begins with which building blocks?

Two protons

Which of the following statements about antimatter is true?

When a particle of matter and the corresponding particle of antimatter meet, they become pure energy