Homework Chapter 1 Complete the following back of the chapter problems for homework for Chapter 1 in the online book. 2. Identify each of the following statements as being most similar to a hypothesis, a law, or a theory. Explain your reasoning. (a) Falling barometric pressure precedes the onset of bad weather. Law; summarizing observations and describes them in some way of the world (b) All life on earth has evolved from a common, primitive organism through the process of natural selection. Theory; testable explanation of particular aspects of nature (c) My truck’s gas mileage has dropped significantly, probably because it’s due for a tune-up. Hypothesis; explanation of observation 8. Why is an object’s mass, rather than its weight, used to indicate the amount of matter it contains? Because its weight is the gravitational force on it; this will change if you move it to another planet or get further away from the Earth. The mass, however, will never change. 9. What properties distinguish solids from liquids? Liquids from gases? Solids from gases? In a solid, molecules are packed together, and it keeps its shape. Liquids take the shape of the container. Gases spread out to fill the container. 10. How does a heterogeneous mixture differ from a homogeneous mixture? How are they similar? Homogeneous exhibits a uniform composition and appears visually the same throughout. and Heterogeneous is mixture with a composition that varies from point to point but both are considered mixtures 11. How does an element differ from a compound? How are they similar? Element is composed of a single atom, compound is a pure substance that can be broken down into different elements. they both have atoms 12. How does an atom differ from a molecule? In what ways are they similar? An atom is the smallest amount of an element you can have and a molecule is the smallest amount of a compound you can have. Molecules are made of atoms, because compounds are made of elements. 24. (c) Antoine Lavoisier, the French scientist credited with first stating the law of conservation of matter, heated a mixture of tin and air in a sealed flask to produce tin oxide. Did the mass of the sealed flask and contents decrease, increase, or remain the same after the heating? I think the mass of the sealed flask Remained the same 40. A large piece of jewelry has a mass of 132.6 g. A graduated cylinder initially contains 48.6 mL water. When the jewelry is submerged in the graduated cylinder, the total volume increases to 61.2 mL. (a) Determine the density of this piece of jewelry. 10.5g/mL (b) Assuming that the jewelry is made from only one substance, what substance is it likely to be? Silver (Density is 10.5 g/mL in Table 1.1.3) 44. Express each of the following numbers in scientific notation with correct significant figures: (a) 711.0 = A) 7.110 x 10^2 (b) 0.239 = B) 2.39 x 10^-1 (c) 90743 = C) 9.0743 x 10^4 (d) 134.2 = D) 1.342 x 10^2 (e) 0.05499 = E) 5.499 x 10^-2 (f) 10000.0 = F) 1.00000 x 10^4 (g) 0.000000738592 = G) 7.38592 x 10^-7