Very small semiconductor crystals, composed of approximately 1000 to 10,000 atoms, are called quantum dots. Quantum dots made of the semiconductor CdSe are now being used in electronic reader and tablet displays because they emit light efficiently and in multiple colors, depending on dot size. The density of CdSe is 5.82 g/cm³. (c) What is the mass of one 6.5-nm CdSe quantum dot?

Very small semiconductor crystals, composed of approximately 1000 to 10,000 atoms, are called quantum dots. Quantum dots made of the semiconductor CdSe are now being used in electronic reader and tablet displays because they emit light efficiently and in multiple colors, depending on dot size. The density of CdSe is 5.82 g/cm³. (a) What is the mass of one 2.5-nm CdSe quantum dot?

(a) One molecule of the antibiotic penicillin G has a mass of 5.342×10^-21 g. What is the molar mass of penicillin G?

Very small semiconductor crystals, composed of approximately 1000 to 10,000 atoms, are called quantum dots. Quantum dots made of the semiconductor CdSe are now being used in electronic reader and tablet displays because they emit light efficiently and in multiple colors, depending on dot size. The density of CdSe is 5.82 g/cm³. (e) If you wanted to make one 6.5-nm dot from multiple 2.5-nm dots, how many 2.5-nm dots would you need, and how many CdSe formula units would be left over, if any?

(b) Hemoglobin, the oxygen-carrying protein in red blood cells, has four iron atoms per molecule and contains 0.340% iron by mass. Calculate the molar mass of hemoglobin.

(a) Ibuprofen is a common over-the-counter analgesic with the formula C₁₃H₁₈O₂. How many moles of C₁₃H₁₈O₂ are in a 500-mg tablet of ibuprofen? Assume the tablet is composed entirely of ibuprofen.