A neutral atom has 20 protons and 21 neutrons. What is the electron configuration of the atom in order of first, second, third, and fourth energy levels?

Which of the following techniques are used to measure residual volume? 1. Helium dilution 2. Body plethysmography 3. Nitrogen washout 4. Flow-volume loops

a. 2 and 4 only b. 1, 2, and 3 only c. 1, 2, 3, and 4 d. 1, 3, and 4 only

What is a normal single-breath diffusing capacity for carbon monoxide for a young, healthy man of average size?

a. 10 ml/min/mm Hg b. 20 ml/min/mm Hg c. 30 ml/min/mm Hg d. 40 ml/min/mm Hg