The formation of the earth and other planetary bodies through the process of condensation and planetary accretion was essentially complete about how many years ago

Primitive meteorites preserve the chemical and isotopic composition of the first aggregates that formed from dust and gas in the solar nebula during the earliest stages of solar system evolution. Gradual increase in the size of solid bodies from dust to aggregates and then to planetesimals finally led to the formation of planets within a few to tens of million years after the start of condensation. Thus the rocky planets of the inner solar system are likely the result of the accumulation of numerous smaller primitive as well as differentiated bodies. The chemically most primitive known meteorites are chondrites and they consist mostly of metal and silicates.Explanation:

answer biscay bay;

heat from the core of the earth causes convection currents to occur in the mantle. these currents slowly move the crust around.