Which of the following changes demonstrates a chemical property? * O A substance breaks in half
A substance combusts (burns)
O A hammer bounces off a substance
O A substance floats in water


The majority of sulfur dioxide produced by industry comes from a. oil refineries. b. dry cleaners. c. chemical plants. d. coal-burning power plants.

Which would best keep the oxygen cycle stable? a. cutting down jungles to create farmland b. eliminating parks in large cities c. dumping toxic chemicals into the ocean d. reducing the amount of deforestation d. reducing the amount of deforestation

Which of the following statements is true? a. there are more chromosomes in an organism than there are genes. b. there are more genes in an organism that there are chemical bases. c. dna is made of sugar, phosphate, and carbon. d. genes are found in specific locations on a chromosome.