What are three conditions that can cause chemical reactions to occur?

The actual density of iron is 7.874 g/mL. In a laboratory investigation, Jason finds the density of a piece of iron to be 7.921 g/mL. What is the percent error that is associated with Jason's measurement? -4.7% -0.6% 0.6% 4.7%

1. Summarize How did the work of scientists who studied fossils support the theory of evolution?

How is the periodic table structured with regard to elements with similar properties?

Marco designs an experiment that will test whether a new plant food makes a grape vine produce more grapes. What is the independent variable in his experiment?

A solid is placed in a solution. Which observation most likely indicates that a chemical reaction has occurred? A.) The size of the solid has rapidly decreased. B.) The color of the solution has not changed. C.

What can form as a result of a chemical reaction?

A solution of orange juice that weighs 500 g contains liquid juice and solid pulp. All of the pulp is removed from the juice. The pulp is found to weigh 50 g. How much would the remaining liquid juice weigh? A. 50 g B. 250 g C. 450 g D. 500 g

Assume 3 molecules of Fe react according to the following equation. 3Fe + 4H2O Fe3O4 + 4H2 How many molecules of H2 are produced? How many water molecules are required? What is the mole ratio of Fe to H2O?

10.0 mL of a HF solution was titrated with a 0.120 N solution of KOH; 29.6 mL of KOH were required to completely neutralize the HF. Calculate the normality of the HF solution.

The number of grams present in 1.35 mol of Fe is