1. Density is defined as   mass × volume   volume / mass   mass / volume   mass × acceleration   Hint Half-n-half Clue   2. Which of the following statements is true?   Water floats on oil because water is more dense than oil.   Oil floats on water because oil is less dense than water.   Oil floats on water because oil is more dense than water.   Water floats on oil because water is less dense than oil.   Half-n-half Clue   3. Hot air is less dense than cold air.   True   False   4. One kg of air is compressed from 1 m3 to 0.5 m3. Which of the following statements is true?   The mass is halved.   The density is doubled.   The mass is doubled.   The density is halved.   Half-n-half Clue   5. The density of water is about 100 kg/m3 at room temperature.   True   False   6. A metal body of mass 81 g occupies a volume of 30 cm3. Identify the metal.   Iron with density = 7.9 g/cm3   Tungsten with density = 19.4 g/cm3   Lead with density = 11.4 g/cm3   Aluminum with density = 2.7 g/cm3   Half-n-half Clue   7. The density of oxygen at room temperature is about 1.3 kg/m3. Therefore, its density in g/cm3 is   1300   0.0013   0.013   130   Half-n-half Clue