Explain what happens to substances during a chemical change.

Which is true of chemicals? a. things containing chemicals always cost a lot of money. b. chemicals are never dangerous. c. chemicals are in many substances in a home. d. chemicals are rarely found on earth.

What is the ph of a solution that has a hydrogen ion concentration of 1.0 * 10 -9 m?

Will mark as brainliest ! how many grams of iron metal do you expect to be produced when 245 grams of an 80.5 percent by mass iron (ii) nitrate solution react with excess aluminum metal? show all work needed to solve this problem!