21. Which food group was reduced the most when comparing the 1990s food pyramid to the current U.S. government's recommendations with MyPlate? Fats & Sw USE SPARINGLY MR Cheese Grup 2-3 GERVINGS SERVINGS A) fruits B) vegetables C) proteins D) grains KEY ofer eng p Paty Dys D) infrared light E) gamma rays 3-4 SERVINGS Waldron, 21st Century Chemistry, 2e, 2019 W. H. Freeman and Company Left: USDA, Center for Nutrition Policy and Promotion 23. Why is it harder to breathe at higher altitudes? A) The % oxygen in air is lower at higher altitudes. B) The % nitrogen in air is higher at higher altitudes. C) The air contains more molecules at higher altitudes. D) The air contains fewer molecules at higher altitudes. Fruits Vegetables 25. Which of the following is not a micronutrient? A) calcium B) iron C) lipid D) vitamin A Grains Protein 22. What do hydrophilic polymers, such as those used in soft contact lenses, contain? A) The polymer contains oxygen atoms that can interact with water via hydrogen bonding. B) The polymer contains oxygen atoms that can interact with water via covalent bonding. C) The polymer contains carbon atoms that can interact with water via hydrogen bonding. D) The polymer contains carbon atoms that can interact with water via covalent bonding. Choose MyPlate.gov 24. Which of the following types of electromagnetic radiation is the least energetic? A) radio waves B) visible light C) ultraviolet light Dairy 26. Atoms of the same element that have different masses are called A) isomers B) allotropes C) isotopes D) molecules 27. The largest energy source for electricity in the U. S. is A) nuclear B) coal C) natural gas D) hydroelectric 28. Fuel cells A) oxidize H to directly produce mechanical energy B) oxidize H to produce electricity C) reduce H to produce electricity D) oxidize O, to produce electricity 4 29. Which of the following hydrocarbons produces the least amount of carbon dioxide per gram when used as a fuel? A) CH B) CH6 C) CH4 D) CH18 30. Two avid runners from different areas of the world are reminiscing about their coldest morning runs ever. An American from Maine has run in 16.9 F weather, whereas a German has run in -7.3 C weather. Which runner has truly run in the colder temperature? A) the German; -7.3 C is colder B) the American; 16.9 F is colder C) There is not enough information given for an accurate comparison D) Both temperatures are the same