Mid-term Test - Earth and Space

At 10,000 degrees Celsius, hydrogen begins to change into helium and energy is released in a process called nuclear fusion, this process occurs in:

• a) Planets. This is the reason planets reflect the sun ́s light.

• b) Stars. That ́s one of the reason stars have their own light.

• c) Earth ́s core. This is the reason the core is melting the mantle.

• d) Stars. This is the reason stars are balls of fire.

The red-shift in the spectral lines of light, reaching us from other galaxies implies that these galaxies ____________.

• a) Are moving closer to one another

• b) Are moving farther apart from one another

• c) Are in rapid rotation

• d) Redshift doesn ́t exist

The age of the universe is probably close to________________

• a) 14 million years

• b) 4 ½ billion years

• c) 15 billion years

• d) 30 billion years

During science class, when we were discussing the universe expansion, we talked about TIME. Why do we say that time is relative? Choose the option that best answers the question.

• a) Time is not relative because Time does not exist it is an illusion. It is not measurable.

• b) Time is relative because it depends on the observer. For example, if the observer is having a good moment, time flies; but if the observer is nod having a good moment, time passes slowly.

• c) Time depends on space and quantum physics. If the observer is looking at the hour it goes slowly.

Hubble's law states that most galaxies are moving ...

• a) away from the Earth, and the further away they are, the slower they are moving

• b) away from the Earth, and the further away they are, the faster they are moving

• c) towards the Earth, and the further away they are, the slower they are moving

• d) towards the Earth, and the further away they are, the faster they are moving

Consider the color of the sun. Based on this color, what is the sun's approximate surface temperature?

• a) 10,000-30,000

• b) 6000-7500

• c) 30000-60000

• d) 3500

Felix examined several photos of stars. To compare their temperatures, he looked at the colors of the stars. He organized the photos in order from coolest to hottest. Which of these answers shows the correct order?

• a) red, yellow, white, blue

• b) white, blue, yellow, red

• c) yellow, white, blue, red

• d) blue, yellow, white, red

Which of the following statements best relates a star’s color to its surface temperature?

• a) blue stars have a relatively low temperature

• b) red stars have a relatively high temperature

• c) blue-white stars have a relatively low temperature

• d) yellow stars have a relatively low temperature

Based on the evidence in the table, which star would appear the dimmest from Earth’s surface?

• a) Star A

• b) Star B

• c) Star C

• d) Star D

About 90 percent of the stars in the universe, including the sun, are main sequence stars. What do all main sequence stars have in common?

• a) All main sequence stars are yellow like our sun.

• b) All main sequence stars are as bright as our sun.

• c) They are all undergoing fusion of helium into carbon within their cores

• d) They are undergoing fusion of hydrogen into helium within their cores