An atom which has 4 protons and 6 neutrons will be electrically neutral if it contains

An atom which has 4 protons and 6 neutrons will be electrically neutral if it contains

A) 4 electrons.
B) 6 electrons.
C) 10 electrons.
D) at least one electron.


Answer: A

Consider an atom of carbon in which the nucleus contains 6 protons and 7 neutrons. What is its atomic number and atomic mass number?

Consider an atom of carbon in which the nucleus contains 6 protons and 7 neutrons. What is its atomic number and atomic mass number? 

A) atomic number = 6; atomic mass number = 13
B) atomic number = 6; atomic mass number = 7
C) atomic number = 13; atomic mass number = 6
D) atomic number = 7; atomic mass number = 13


Answer: A

Suppose that two stars are identical in every way—for example, same distance, same mass, same temperature, same chemical composition, and same speed relative to Earth—except that one star rotates faster than the other. Spectroscopically, how could you tell the stars apart?

Suppose that two stars are identical in every way—for example, same distance, same mass, same temperature, same chemical composition, and same speed relative to Earth—except that one star rotates faster than the other. Spectroscopically, how could you tell the stars apart? 

A) The faster rotating star has wider spectral lines than the slower rotating star.
B) The faster rotating star will have an emission line spectrum while the slower rotating star will have an absorption line spectrum.
C) The peak of thermal emission will be at a shorter wavelength for the faster rotating star than for the slower rotating star.
D) There is no way to tell the stars apart spectroscopically, because their spectra will be identical.


Answer: A

Studying a spectrum from a star can tell us a lot. All of the following statements are true except one. Which statement is not true?

Studying a spectrum from a star can tell us a lot. All of the following statements are true except one. Which statement is not true? 

A) The total amount of light in the spectrum tells us the star's radius.
B) The peak of the star's thermal emission tells us its temperature: hotter stars peak at shorter (bluer) wavelengths.
C) We can identify chemical elements present in the star by recognizing patterns of spectral lines that correspond to particular chemicals.
D) Shifts in the wavelengths of spectral lines compared to the wavelengths of those same lines measured in a laboratory on Earth can tell us the star's speed toward or away from us.


Answer: A