Answer Happy

1. A substance that cannot be separated into two or more substances by physical means is: a. a compound b. an element c. either a compound or an element d. a homogeneous mixture e. a heterogeneous mixture 2. Which of the following statement(s) is(are) not correct? a. The conversion of compounds into elements is a chemical change. b. The conversion of sugar into carbon and water is a chemical change. c. The conversion of elements into compounds is a chemical change. d. The conversion of liquid water into gaseous water is a chemical change. e. The evaporation of water is a physical change. f. d and e 3. Which of the following is a mixture? a. glucose (C6H12O6) b. an alloy made of varying amounts of Au and Pb c. chlorine gas (Br2) d. both a and b e. both c and d Convert the following numbers into exponential notation and report them to 2 significant digits: 4. 0.04756 m 5. 32237.89 ng 6. -0.00888 J 7. A 10.33 mL sample of methylene chloride has a density of 1.32 g/cm³. What is the mass in kg of methylene chloride? a. 1.36x10 kg b. 1.28x10 kg c. 0.0136 kg d. 1.36x10³ kg e. 1.99x10¹¹ kg