Which accurately describes coral reefs? Select the three correct answers.(2 points)

Question

Responses

Coral reefs are sturdy structures that can exist for thousands of years.
Coral reefs are sturdy structures that can exist for thousands of years.

Coral reefs are delicate structures that usually exist for less than 10 years.
Coral reefs are delicate structures that usually exist for less than 10 years.

Coral reefs often are located in nutrient-rich waters.
Coral reefs often are located in nutrient-rich waters.

Coral reefs often are located in nutrient-poor waters.
Coral reefs often are located in nutrient-poor waters.

Coral reef ecosystems are among the most biodiverse on Earth.
Coral reef ecosystems are among the most biodiverse on Earth.

Coral reef ecosystems have low biodiversity.

Answer 1

The three correct answers that accurately describe coral reefs are:

1. Coral reefs are sturdy structures that can exist for thousands of years.
2. Coral reefs often are located in nutrient-poor waters.
3. Coral reef ecosystems are among the most biodiverse on Earth.

Answer 2

Which is a difference between visible light and radio waves?(1 point)
Responses

Radio waves have less energy than visible light.
Radio waves have less energy than visible light.

Radio waves have more energy than visible light.
Radio waves have more energy than visible light.

Radio waves can produce rainbows.
Radio waves can produce rainbows.

Radio waves can be seen by the human eye.

Answer 3

The correct answer that describes a difference between visible light and radio waves is:

Radio waves have less energy than visible light.

Answer 4

Which does the shift of the hydrogen absorption spectrum of a galaxy provide evidence for? Select the three correct answers.(2 points)
Responses

composition of the universe
composition of the universe

temperature of the galaxy
temperature of the galaxy

motion of the galaxy
motion of the galaxy

The Big Bang theory
The Big Bang theory

number of stars in the galaxy
number of stars in the galaxy

expansion of the universe

Answer 5

The three correct answers that the shift of the hydrogen absorption spectrum of a galaxy provides evidence for are:

1. motion of the galaxy
2. The Big Bang theory
3. expansion of the universe

Answer 6

Which one of these statements is true of the brightest stars?(1 point)
Responses

Several are white dwarfs.
Several are white dwarfs.

Each is part of the main sequence.
Each is part of the main sequence.

Many are supergiants.
Many are supergiants.

They are yellow stars.

Answer 7

The true statement of the brightest stars is:

Many are supergiants.

Answer 8

Use the diagram to answer the question.



A graph illustrates the relationship between the luminosity (Sun = 1), ranging from 0.0001 to 10000, and temperature in Kelvin, ranging from 30000 to 3000, for various stars classifications. Main sequence stars extend diagonally from the top left to the bottom right corner of the graph. The White Dwarfs, Giants, and Super Giants are placed on the graph according to their luminosity and temperature.


If a star has an absolute magnitude of 10 and a temperature of 20,000 K, under which spectral class would the star be classified?

(1 point)
Responses

B
B

O
O

A
A

F

Answer 9

Based on the provided temperature of 20,000 K, the star would be classified under the spectral class:

B

Stars in the B spectral class typically have temperatures ranging from about 10,000 K to 30,000 K.

Answer 10

Select the correct answer from the list.(1 point)
The main light element that can be produced in stars is
Select Answer
. The heaviest element that can be produced in large stars is
Select Answer
.

Answer 11

The main light element that can be produced in stars is hydrogen. The heaviest element that can be produced in large stars is iron.