Surface ocean currents are caused by ________, whereas deep currents are the result of _______.

________ was the first astronomer to track sunspot movement with the aid of a telescope which was a huge advantage over his astronomical predecessors.

________ is the proportion of dissolved salts to 1000 g sample (g of salt/1 kg water).

The volcanic activity in Yellowstone National Park and Hawai’i is caused by ________.

If a spit grows as it is deposited and extends completely across the former mouth of an estuary, separating it from the open sea, it has become a ________. (Diagram provided to help you visualize, letters are not relevant for this question)

According to the ________, the Earth, Sun, and solar system began to form about 4.6 billion years ago from the gravitational collapse of a huge cloud of dust and gases.

A ________ is a barrier built at a right angle (perpendicular) to the beach to trap sand that is moving parallel to the shore.

What did Tycho Brahe believe was at the center of our planetary system?

A rainshadow desert forms:

The molecule below has sigma (σ) and pi (π) bonds. How many are of pi (π) type?