CH 16 HW

Convection Zone

Layer of the Sun where energy moves by rising hot gas and falling cooler gas.

Photosphere

Visible surface of the Sun from which most of the light is emitted.

Chromosphere

Narrow layer of the Sun from which most of its ultraviolet light is emitted.

Corona

Outer atmosphere of the Sun that can be seen during total solar eclipses.

Radiation Zone

Layer of the Sun between its core and convection zone.

Stable Star

A protostar becomes a stable star when it reaches the necessary temperature for nuclear fusion.

Sun's Diameter Compared to Earth's

The Sun's diameter is approximately one hundred times larger than Earth's.

Average Density of the Sun

The Sun's average density is roughly the same as that of water.

Solar Constant on Venus

The solar constant measured on Venus would be larger than that on Earth.

Density vs. Temperature in the Sun

As distance from the center of the Sun increases, density decreases faster than temperature decreases.

Typical Solar Granule Size

A typical solar granule is about the size of a U.S. city.

Temperature in the Sun's Atmosphere

The temperature in the Sun's atmosphere steadily increases as we move above the photosphere.

Sunspot Maxima

The time between successive sunspot maxima is about a year.

Primary Source of the Sun's Energy

The primary source of the Sun's energy is the fusion of light nuclei to make heavier ones.

Conditions for Fusion

Fusion occurs under extremely high temperature due to protons repelling each other, requiring high speeds for close proximity.

Particle Produced in Proton-Proton Fusion

The particle produced in the proton-proton fusion reaction is a neutrino.

Solar Neutrino Problem

The solar neutrino problem is that we detect fewer solar neutrinos than we expect.