Question

how were Continental masses and ocean floors formed?

Answer 1

Dear Student,
Initially, there was only one ginormous piece of land named Pangea. Later on due to continental drifting, i.e. due to the movement of tectonic plates within the earth and thereby breaking apart of Pangea the rest of the continents were formed. Pangea first broke into Laurasia and Gondwanaland. These later broke into the modern-day continents.
Hess a research scientist in his own words agued that "constant eruptions at the crest of oceanic ridges cause the rupture of the oceanic crust and the new lava wedges into it, pushing the oceanic crust on either side." He called it the seafloor spreading hypothesis
Regards