Which statement is true of pure substances? They can contain different types of atoms and molecules. They may contain one type of atom or one type of molecule. They can only contain one type of molecule. They can only contain one type of atom

What is the nature of the ca-cl bond in a molecule of calcium chloride (cacl2) if the electronegativity value of calcium is 1.0 and that of chlorine is 3.16?

Which of the following is an example of physical change not a chemical change? a) a log gives off heat and light as it burns. b) a tree stores energy from the sun in its fruit. c) a penny lost in the grass slowly changes color. d) a water pipe freezes and cracks on a cold night.

1) describe the physical layout of the ocean floor ? 2) explain how the dumbo octopus swims differently than other octopus species and why this would be an advantage in the aphonic zone . 3) why are the types of organisms that live at each underwater hot vent so dramatically different ?