Takes two small nuclei and combines them into a larger nucleus

• fission
• fusion

The splitting of a nucleus into smaller nuclei is

• fusion
• fission
• half-life
• gamma radiation

How do nuclear power-plants work?

• Fusion
• Half-life
• Fission
• Fusion or fission

Where does fusion occur naturally?

• Underwater
• All around us
• In the radioactive waste
• On the sun

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

• supernova
• pulsar
• nuclear fusion
• nuclear fission

All stars begin their life in a

• Main Sequence
• Nebula
• Protostar
• Black Dwarf

What are the final two stages of a medium mass star?

• white dwarf - black dwarf
• neutron star - black hole
• supernova - neutron star
• pulsar - neutron star

The life cycles of stars are determined by their:

• mass (size)
• color
• distance from Earth
• luminosity

______ is a force that causes dust particles to stick together in a nebula.

• nuclear fusion
• gravity
• hydrogen
• friction

Most stars are made of which elements?

• Hydrogen only
• Hydrogen and Lithium
• Hydrogen and Sodium
• Hydrogen and Helium