Which of the following is not an example of a chemical change?

digesting food
burning gas in an engine
cooking eggs
grinding pepper

Which of the following pressures is equal to 760 mm hg? 2.0 atm 101.3 pa 101,300 kpa 101,300 pa

There are main groups in the modern periodic table of elements

Which best describes the present-day universe? opaque, expanding very slowly, stars produce heavy elements transparent, expanding at an accelerated rate, stars produce heavy elements opaque, expanding at an accelerated rate, stars produce only hydrogen and helium transparent, expanding very slowly, stars produce only hydrogen and helium