15. Which of the following islare used to classify a star based on its temperature and luminosity? O A. Line spectra
O B. Hertzsprung-Russell diagram
O C. Blackbody spectrum
O D. Parallax measurements

water at room temperature is flowing through a pipe with pressure taps located 10 ft apart along one section of the pipe, which are connected to a mercury (s=13.6) manometer.

1. a)c-14 has two more protons

2. d)they have different numbers of protons, neutrons, and valence electrons; they are all gases at room temperature.

3. c) iron and nickel.

the correct answer is c