In 1859, a chemist observed a naturally occurring substance on oil drilling equipment. oil workers would rub the substance on their skin to help heal cuts and burns. the chemist took this black, waxy substance back to his laboratory. he discovered that the substance formed a waterproof barrier on damaged skin that helped seal in moisture. after 10 years of experiments distilling, cleaning, and filtering the substance, the chemist developed a new product that he called "petroleum jelly." the product was semisolid, was pale yellow in color, and had no taste or smell. the product could be used to treat dry skin, cuts, and burns. which physical property of the petroleum jelly makes it useful for healing dry skin, cuts, and burns?