What is the partial pressure of argon gas in a sealed vessel that has a total pressure of 1514 psi and partial pressures of 325 psi for oxygen and 649 psi for nitrogen?

The total pressure of a gas is equivalent to the sum of partial pressures of the individual components of the gas. Here, there are three gases, argon, oxygen and nitrogen. Therefore:
Total pressure = PP nitrogen + PP oxygen + PP argon
1,514 = 649 + 325 + PP Argon

The partial pressure of argon then works out to be 540 PSI.

1. and 2. question: in which equation? or i don't understand you, 3. a), 4. c), 5. c), 6. b), 7. d), 8. d) if small number is underlined(behind symbol) , b) if big number is underlined(in front of symbol)9. what is underlined there? 10. c)

The correct answer should be "electrons orbit the nucleus in circular motions exactly as shown on the classic bohr model."