If the cube is 3 cm on each side, then it has a volume of 27 cm^3 (3 x 3 x 3). Density is mass divided by volume, so its density is 72.9/27 = 2.7 g/cm^3.
<span>Going by the density, the cube is made of Aluminium - density is a fairly unique quantity</span>
Answers:
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1) [D]: " CO₂ " .
<u>Note:</u><u> </u> This is the only answer choice given that is composed of: "at least two different elements" .
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2) [D]: "carbon and hydrogen" {"C" and "H" .} .
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<span>lower than the boiling point of water
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h2+o2=2h2o.................................................