Which of the following is a clue of a chemical change? a. balls of wax form when melted wax is poured into ice water b. gas bubbles form in boiling water c. a gas forms when vinegar and baking soda are mixed d. iron changes color when heated

What effect does plate tectonics have an organic evolution

Type the correct answer in each box. use numerals instead of words. if necessary, use / for the fraction bar. the following chemical equation shows the combustion of ethane. balance the equation by filling in the coefficients. c2h6 + o2 → co2 + h2o

The pharynx is the structure in the body that serves as a pathway of both air and food. how does the body make sure that food does not get into the lungs? the salivary glands secrete enzymes that pull food out of the air pathway. the small intestine pushes the air out of the digestive system. the pancreas breaks down food in the air pathway. the epiglottis closes the air pathway so that food will not enter it.