Make a prediction that describes the relationship between the composition of an unknown substance and its emission spectrum. for example, “if each element can be identified by its then the of an unknown star can be determined."

Which of the following statements about acidic water is true? a. acid has no effect on the h,o molecules. b. the solution contains a larger number of oh ions than h,o ions. c. the solution contains a larger number of h,o ions than qh ions. d. the solution contains an equal number of h,o ions and oh ions. none of the above e.

The characteristic of two different types of reactions are shown below. reaction a: electrons are gained by the atoms of an element. reaction b: protons are lost by the atom of and element. which statement is true about the atoms of the elements that participate in the two reactions? a: their identity changes in both reaction a and b. b: their identity changes in reaction a but not b. c: their identity changes in reaction b but not a. d: their identity remains the same.

Ablock of aluminum is dropped into a graduated cylinder with an initial volume of water at 75ml and the volumes rises to 90ml. if the block has a mass of 40.5 g what is its density ?