1. Most stars tend to form in large clouds of gases in space. What are these clouds called? Accretion disks Galaxies Nebulae Quazars

2. Which element contained in nebular clouds acts as the fuel for newly-formed stars? Hydrogen Oxygen Helium Petrolium

3. When gases and dust in nebulae start gathering together due to gravity, they form into large clumps. What are these clumps of gas and dust known as? Bok globules Star-process clusters Globular clusters Nebules

4. When the gas/dust compression due to gravity is balanced by the pressure created inside the forming star, what state is said to have been achieved? Hydrostatic equilibrium Core-Pressure balance Graviostatic balance Nuclear equilibrium

5. Once a star has gathered enough mass and achieved hydrostatic equilibrium, the pressure (and resultant increased temperature) ignites nuclear fusion in the star's core. It will spend approximately the next 90% of its life fusing hydrogen into helium. What is this stage of the star's life called? Major sequence Prime sequence Main sequence Hydrogen sequence

6. Once the hydrogen in the star's core is used up, the star begins to change dramatically. What change first takes place after the main sequence? The star starts shrinking The star explodes The star starts breaking apart The star starts expanding

7. Once the hydrogen is all used up, a star will begin fusing the helium instead. Heavier stars will be able to fuse progressively heavier elements together, if their masses can support it. One element, however marks the end of regular fusion in a star's core, as it cannot be fused any further. Which element is this? Carbon Sulphur Zinc Iron

8. If the mass of the star's core exceeds a critical mass point (called the "Chandrasekhar Limit"), the star experiences a catastrophic explosion called a supernova. What happens in the core of a supernova? Neutrons are formed The star restarts its life cycle Nuclear fission begins All activity stops

9. Once neutron stars exceed a certain critical mass, even the neutrons are compressed to such a state that their composition particles are forced together. The core is packed together so tightly, that a "singularity" is believed to have been formed. This creates what is known as a black hole. What are the particles that make up a neutron called? Neutrinos Quarks Bosons Photons

10. While a black hole signifies the ultimate end to a star's life cycle, it is not the only way for a star to end its life. Which of the following is not a final stage of a star? White dwarf Neutron star Brown dwarf Protostar