Match each stage to its correct description:

Stages:

1. Protostar
2. Main Sequence Star
3. Supernova
4. White Dwarf

Descriptions:

• A: A hot, dense remnant left behind after a low-mass star ceases nuclear fusion in its core.
• B: An early stage of stellar evolution formed by the gravitational contraction of an interstellar cloud.
• C: A colossal stellar explosion that disperses heavy elements into space.
• D: The longest, stable stage of a star's life during which hydrogen is converted into helium in its core.

Which stage in the lifecycle of a star with a mass similar to our Sun immediately follows the main sequence? Select from: red giant, red supergiant, neutron star, black hole.

What process in the core of a star provides the energy to produce the outward radiation pressure opposing gravity? Select from: chemical combustion, nuclear fission, nuclear fusion, beta decay.

Complete the sentence describing a star on the stable main sequence. Select from: equal to, greater than, less than.

"The outward radiation pressure of the star is ____________________ the inward pull of gravity."

Consider the two nuclear equations represented below:

• Equation P: ${}_6^{12}C+{}_2^{4}He\to {}_8^{16}O$
• Equation Q: $n+{}_{94}^{239}Pu\to {}_{54}^{134}Xe+{}_{40}^{103}Zr+3n$

Which equation shows nuclear fusion? (Answer P or Q)

Which equation shows nuclear fission? (Answer P or Q)