What characterizes a chemical change?

The pH of a solution is 7.880. What is the concentration of [H30+] in the solution?

Which would be a better base to use if you wanted to remove a proton from ethyne?

A 200-gram sample of a radioactive nuclide is left to decay for 60 hours. At the end of 60 hours, only 25 grams of the sample is left. What is the half-life of the nuclide sample? 60 hours 30 hours 40 hours 20 hours - - - > I think 20?

Why does the moon have phases? What are the four main phases of the moon? How long does it take to change from one to another?

The density of aluminum is 2.70g/mL. What is the volume in mL of 74.5 grams of aluminum?

Explain Charles law

2 H2 + O2 → 2 H2O What is the product of this chemical reaction

Which of the following is a chemical property? A.) Ability to burn B.) Mass C.) Density D.) All of the above

What is the density of rock if it has a mass of 25 g?

In a popular classroom demonstration, solid sodium is added to liquid water and reacts to produce hydrogen gas and aqueous sodium hydroxide. part a write a balanced chemical equation for this reaction.