PS unit review 1

According to the Big Bang Theory, what is believed to have happened right after the universe began?

• The universe started contracting.

• Stars and galaxies began to form.

• The universe cooled down gradually.

• Atoms like helium were destroyed.

Which of the following formed first in the solar system?

• The planets

• The Sun

• The asteroid belt

• The solar nebula

What is dark matter?

• A type of star

• A substance that emits light

• Matter that does not emit electromagnetic radiation

• A type of nebula

What discovery by Vera Rubin supported the existence of dark matter?

• Stars form in clusters.

• Galaxies spin faster than expected from their visible matter.

• The universe is expanding.

• The Sun has a magnetic field.

Which phenomenon is evidence of dark energy?

• Stars forming in a nebula

• The accelerating expansion of the universe

• The presence of black holes

• The gravitational collapse of a star

What is the sequence of events in the formation of planetesimals?

• Dust grains form, collide, then gather more atoms.

• Matter collides, dust grains form, then gather atoms.

• Matter forms around dust grains, then collides.

• Atoms gather, dust grains form, then matter collides.

In the process of gravitational condensation, what happens to the object?

• It gets smaller due to loss of material.

• It increases in size due to the addition of materials.

• It becomes a star.

• It turns into a nebula.

Which of the following is true about a nebula?

• It is a dense, hot core of a star.

• It is a cloud of gas and dust in space.

• It is the remnant of a supernova explosion.

• It is the remains of a planetesimal collision.

Which characteristic is used to classify stars on the Hertzsprung-Russell diagram?

• Distance from Earth

• Color and temperature

• Size and brightness

• Temperature and absolute brightness

What is the main element in most stars?

• Helium

• Hydrogen

• Oxygen

• Carbon