(a) A CHM 101 student obtains the number 0.045005700 on a calculator. If this number actually has four (4) significant figures, how should it be written? (b) Express the number 0.00000333 in scientific notation. (c) Change the units: (i) 5055 mm to m (ii) 543.7 dm to m (iii)0.0005359 kg to mg 2. Lithium is a soft, gray solid that has the lowest density of any metal. It is an essential component of some advanced batteries, such as the one in your laptop. If a small rectangular slab of lithium weighs 1.49 x 103 mg and has sides that measure 20.89 mm by 11.1 mm by 11.899 mm, what is the density of lithium in g/cm? 3. Student B collected 5.4kg of aluminum from a recycling bin. (i) Calculate the number of moles of aluminum. (ii) How many Aluminium atoms were collected? 4. Two stable isotopes of lithium, Li and Li, have respective abundances of 7.5% and 92.5%. Li isotope has the mass of 6.015 amu and the relative atomic mass of lithium is 6.941 amu. Calculate the mass of Li. 5. A 60kg woman has 1.13kg of heamoglobin (64,456 g/mol) in her blood. How many molecules of hemoglobin are in her blood? 6. Student C carried out the combustion analysis of adipic acid which contains C, H and O only. The mass percentages of C and H are 49.3% and 6.9% in adipic acid respectively. (i) Distinguish between empirical and molecular formula. (ii) What is the empirical formula of adipic acid ? (iii) The molecular formula mass of adipic acid is about 146 g/mol. What is its molecular formula?