ANSWERS AT THE END OF EACH CHAPTER CHAPTER 1: Portable Electronics: The Periodic Table in the Palm of Your Hand Emphasizing Essentials 1. Answer: a. Compound (2 molecules of one compound made up of two different elements). b. Mixture (2 atoms of one element plus 2 atoms of another). c. Mixture (3 different substances, two elements and one compound). d. Element (4 atoms of the same element). 2. Answer: a. element (4 molecules of one diatomic element) b. Compound (2 molecules of one compound made up of two different elements). c. Mixture (2 atoms of one element plus 2 atoms of another). d. Compound (4 molecules of one compound made up of two different elements). 3. Answer: Exact answer will vary depending on viewing size of text. An approximate measurement for the period could be 0.25 mm. Converting this to nanometers: 0.25 mm × 10 -3 m × 1 nm = 2.5×105 nm or 250,000 nm. 1 mm 10-9 m 4. Answer: Converting 10.0 nanometers to millimeters: 10.0 nm × 1 m 1×109 nm × 1000 mm = 1 × 1 m 10−5 mm or 0.00001 mm. 5. Answer: a. 1.5  103 m b. 9.58  10–11 m c. 7.5  10–6 m 6. Answer: 1×10