Mock Unit Test in Physical Science

What process led to the formation of light elements in the early universe?

• Nuclear fission

• BBN

• Stellar fusion

• Radioactive decay

When did Big Bang nucleosynthesis occur?

• Within the first 20 minutes after the Big Bang

• One billion years after the Big Bang occurs

• During the formation of very large stars

• After the Milky way galaxy and others were formed

Which element is most abundant in the universe due to Big Bang nucleosynthesis?

• Helium-4

• Lithium-7

• Hydrogen-1

• Carbon-12

What evidence supports the formation of light elements during the Big Bang?

• The abundance ratios of hydrogen, helium, and lithium in old stars and galaxies.

• Large presence of oxygen and nitrogen in interstellar space from the early universe.

• The formation of carbon and oxygen during supernovae.

• Observations of iron-rich stars.

Which element formed during Big Bang nucleosynthesis is only present in trace amounts?

• Helium-4

• Deuterium

• Lithium-7

• Carbon-12

Where do heavier elements like carbon and oxygen form?

• During Big Bang nucleosynthesis

• During black hole formation, the death of a star

• In the interstellar medium such as outside the Milky Way galaxy

• In the cores of stars through nuclear fusion

What is the primary reaction responsible for the formation of carbon in stars?

• Proton-proton chain reaction

• Slow neutron capture (s-process)

• Rapid neutron capture (r-process)

• Triple-alpha process

Why does nuclear fusion in stars stop at iron?

• Iron fusion releases too much energy.

• Iron fusion is exothermic and self-sustaining, a viable fuel.

• Iron fusion absorbs energy rather than releasing it.

• Stars run out of hydrogen before fusing iron and other heavier elements.

What happens when a massive star's core collapses after iron formation?

• It becomes a white dwarf.

• It produces hydrogen through nuclear fission.

• It undergoes Big Bang nucleosynthesis again.

• It explodes as a supernova.

Which process produces elements heavier than iron, such as gold and uranium?

• Proton-proton chain reaction

• Triple-alpha process

• Rapid neutron capture

• Deuterium fusion