The orbits of population I stars I. are confined to disk of the galaxy. II. are very elliptical. III. are nearly circular. IV. are randomly inclined to the disk of the galaxy.
a. I
b. IV
c. I & IV
d. II & IV
e. I & III
Question 2
Opacity is
a. the balance between the pressure and force of gravity inside a star.
b. the force that binds protons and neutrons together to form a nucleus.
c. the force that binds an electron to the nucleus in an atom.
d. a measure of the resistance to the flow of radiation (photons) through a gas.
e. the temperature and density at which a gas will undergo thermonuclear fusion.
Exponential growth in the Canadian migratory population of the whooping crane after 70 years of cons
The two bright stars are (left) Alpha Centauri and (right) Beta Centauri.
The Types of Stars and Their Sizes
World Population Growth, 1750-2150
The developing and emerging nations have high rates of population growth
The population of a city has continued to grow since 1950.