According to the law of conservation of matter, which statement about chemical reactions is true?
a. every atom destroyed in a chemical reaction must be replaced.
b. atoms are created by some reactions and destroyed by others.
c. atoms cannot be created or destroyed by chemical reactions.
d. energy is created as atoms are destroyed in chemical reactions.

The chart shows the bid provided by four contractors to complete a job. which contractor is the most cost-effective?

Achemistry student weighs out 0.306 g of citric acid (h3c6h5o7), a triprotic acid, into a 250 ml volumetric flask and dilutes to the mark with distilled water. he plans to titrate the acid with 0.1000 m naoh solution. calculate the volume of naoh solution the student will need to add to reach the final equivalence point. be sure your answer has the correct number of significant digits.

What type of matter is made of only one kind of atom