The Local Group of galaxies spans about 30 million light-years in diameter.
Indicate whether the statement is true or false
Question 2
Energy balance in the Sun refers to a balance between ________.
A) the force of gravity pulling inward and the force due to pressure pushing outward
B) the amount of energy the Sun radiates into space and the amount of energy that reaches Earth
C) the rate at which fusion generates energy in the Sun's core and the rate at which the Sun's surface radiates energy into space
D) the mass that the Sun loses each second and the amount of mass converted into energy each second
Why leaves are green: interaction of light with chloroplasts.
Assessment of Light Touch
U.S. adults from 25 to 74 years report that the largest proportion of their daily stressors arise ...
Group Size
Average Years of Schooling versus GDP per Capita
Trends in employed mothers with a child/children younger than 3 years of age