What conditions were necessary for Africa and South America to move apart?

Given what you know about acids and bases, which of the following descriptions is the most accurate? A. We can tell a substance is acidic if it had a high pH B. A basic substance has a low pH C.

What kind of bond is not formed by differences in electronegativity? A) ionic B) polar disalent C) polar covalent D) nonpolar covalent

He 64.8-g sample of the compound X2O5 contains 48.0 g of oxygen atoms. What is the molar mass of element X?

What did Darwin observe about finches in the Galápagos Islands? a. Their feathers were adapted to match their environment. b. Their beaks were adaptations related to the foods the finches ate. c. They had identical phenotypes in all locations. d.

A chemist dissolves 156. mg of pure hydrobromic acid in enough water to make up 220. mL of solution. Calculate the pH of the solution. Be sure your answer has the correct number of significant digits.

What can cause tsunamis? Select all that apply. spring tides plate movement volcanic activity earthquakes hurricanes

On the maxillary left side, there's only one posterior tooth, which is large and has a fifth cusp and three roots. this tooth is a maxillary a. central incisor. b. second premolar. c. third molar. d. first molar.

How do the rates of the forward and reverse reactions change throughout a reaction?

An unknown solution turned red litmus paper red, turned blue litmus paper blue, and didn't conduct electricity. The solution is most likely ... a Basic b Acidic c Neutral d Not enough information to determine

Which of the following does NOT occur at a subduction zone? A. The leading edges of both plates are bent downward. B. Oceanic crust is pushed down into the mantle. C. One oceanic plate moves into another oceanic plate. D.