Question

For problems 11 through 13, show your work to receive full credit and use the correct number of significant figures in your final answer. 11. The density of nickel is 8.91 g/cm3. Calculate the mass of a nickel ball with a radius of 0.50 mm in grams. (π = 3.1416; Vsphere = 4πr3/3) 12. The recommended adult dose of Elixophyllin , a drug used to treat asthma, is 6.00 mg/kg of body mass. Calculate the dose in milligrams for a 134-lb person. 13. It is 273 K outside. Do you need a jacket? Why or why not? (show your work for full credit) 14) Element X has three naturally occurring isotopes. The masses (amu) and % abundances of the isotopes are given in the table below. What is the average atomic mass of the element in amu? isotope38 abundance of 5.07,mass of 37.919 isotope39x,abundance of 15.35,mass of 39.017 isotope 42,abundance of 79.85,mass of 42.111 15. Classify each of the following elements as alkali, alkaline earth, halogen or a noble gas: a) He ________________________ b) F ________________________ c) Na ________________________ d) Ca ________________________ e) Br ________________________