6. Which of the following happens to the temperature of gases as they reach the top of the sun's convection zone?
a. it increases
b. it decreases
c. it does not change***
d. there is no way to tell what happens
7. Which of the following does a star's absolute brightness depend on?
a.distance and temperature***
b. size and temperature
c. color and temperature
d. distance and color
To answer question 6, we can consider the concept of the sun's convection zone and how gases behave in this region. The convection zone is the outermost layer of the sun's interior, where energy is transported by convection currents, similar to boiling water. When gases rise to the top of the convection zone, they undergo changes.
Option a, it increases: The temperature of gases does not increase as they reach the top of the sun's convection zone. This is because the temperature gradient in the convection zone is not strong enough to cause a significant increase in temperature.
Option b, it decreases: The temperature of gases does not decrease as they reach the top of the convection zone. Since heat energy is being transported upwards through convection currents, the temperature remains relatively constant.
Option c, it does not change: This is the correct answer. As gases rise to the top of the convection zone, their temperature remains relatively constant.
Option d, there is no way to tell what happens: We can determine what happens to the temperature of gases in the convection zone based on our understanding of how convection currents work. The temperature does not increase or decrease significantly; it remains constant.
Moving on to question 7, we need to examine what factors affect a star's absolute brightness.
Option a, distance and temperature: This is the correct answer. A star's absolute brightness depends on its distance from Earth and its temperature. The distance affects how much light reaches us, whereas the temperature affects the overall energy output of the star.
Option b, size and temperature: While the size of a star can impact its brightness, the question specifically asks about the star's absolute brightness. The absolute brightness of a star primarily depends on distance and temperature.
Option c, color and temperature: Although the color of a star can provide information about its temperature, the question specifically asks about the absolute brightness. The color alone does not determine the absolute brightness of a star.
Option d, distance and color: While the distance and color of a star can affect its overall appearance and visibility, they do not directly determine the star's absolute brightness. The absolute brightness depends on the distance and temperature.