Seafloor spreading and continental drift are believed to be caused by

Convection current

Explanation:

The seafloor spreading refers to the splitting of the oceanic crust in two opposite direction, resulting in the expansion of the ocean basin. And the continental drift refers to the large scale movement of the continents from one location to another, over the vast ocean water bodies.

Both these processes are believed to be caused by the convection current, that generates in the mantle portion of the earth. In the mantle, the magma being less dense, rises from the interior of the earth, and as it rises upwards, it forms convection cells, that forces the plates to move in different directions sharing a type of plate boundary. This entire process is known as the plate tectonic movement.

within these regions are all the major types of biomes in the world. a biome is a community of animals and plants spreading over an extensive area with a relatively uniform climate. some diverse biomes represented in north america include desert, grassland, tundra, and coral reefs.

because the two particles have an equal charge, the charges will cancel out and give the atom an overall charge of 0. so, if at atom has 35 protons in the nucleus, we could expect it to have 35 electrons orbiting that nucleus.