The Nebular Hypothesis suggests that planets were formed out of a cloud of material associated with a ___ sun.

Youthful

Fill in the blank: In the revised version of the Nebular Hypothesis, scientists suggested that the sun was surrounded by a solar ___ containing mainly hydrogen and helium.

Nebula

Fill in the blank: The original Nebular Hypothesis was revised in ___ and ___ by Otto Schmidt and Carl Weizascar.

1950, Germany

True or False: Later scientific inquiries shifted focus from the origin of the universe to the origin of just the earth and planets.

False - Later scientific inquiries focused on the origin of the universe rather than just the earth or the planets.

The Big Bang Theory posits that the universe is in a constant state of ___ since the explosion occurred approximately 13.7 billion years ago.

Expansion

True or False: The first atoms in the universe formed within three minutes after the Big Bang explosion.

True

What occurred about 300,000 years after the Big Bang, allowing the universe to become transparent?

The temperature dropped to 4,500K, leading to atomic matter formation.

True or False: Stars formed before the Big Bang explosion.

False. Stars formed after the Big Bang explosion, approximately 5-6 billion years ago.

What is the significance of the singularity in the context of the Big Bang Theory?

The singularity represents a state where all matter and energy existed in an infinitely dense and hot point before the Big Bang explosion.

Stars form from localized lumps of gas within a ___, where gravitational forces create a core.

Nebula

True or False: The gas cloud condenses into larger objects called planetesimals through gravitational attraction and sticking together.

True

The process through which numerous small planetesimals accrete to form larger bodies is known as ___.

Accretion

Initially, Earth's atmosphere was primarily composed of which two gases?

Hydrogen and helium

Fill in the blank: The separation of materials inside the Earth based on density during its evolution led to layers such as the crust, mantle, outer core, and ___ core.

Inner

True or False: The cooling process of Earth resulted in an increase in size and the formation of a solid outer crust.

False; the cooling process led to the development of the outer crust and a decrease in size.