5.7_Exit Ticket

Put the following sequence of events in the correct order. You may use the attached diagram for help.

1. The nebula grows denser at the center, condensing into an accretion disk
2. Protoplanets form on the edges of the accretion disk, denser rocky planets closer to the middle, lighter gas planets on the outside
3. A cloud of gas (nebula) forms
4. Protoplanets condense and differentiate into fully developed planets
5. The center of the nebula grows so dense that fusion occurs, forming a protostar