How many significant figures are in the number 420,000 mi?

Black round and partialy brown with little hairs that stick out, or a little creature that digs in the dirt that has wird pink whiskers in the front of its nose thats partily blind

1.from liquid state to gaseous state is evaporation 3.solid to liquid is melting 5. solid to gaseous state is sublimation 6. gas to solid state is decomposition 7. a change of state is known as the states of matters