Answer:
The climate of the earth throughout history has always been <em><u>fluctuated between hot and cold periods. </u></em>
Answer:
The farther star will appear 4 times fainter than the star that is near to the observer.
Explanation:
Since it is given that the luminosity of the 2 stars is same thus they radiate the same energy per unit time
Consider a spherical wave front of energy 'E' that leaves both the stars (Both radiate 'E' as they have same luminosity)
This Energy is spread over the whole surface area of sphere Thus when the wave front is at a distance 'r' the energy per unit surface area is given by
For the star that is twice away from the earth the distance is '2r' thus we will receive an energy given by
Hence we sense it as 4 times fainter than the nearer star.
The atomic number is the same as the proton number so the answer would be D) 10
Answer:
different number of mass numbers.
Explanation:
isotopes are atoms of the same element having the same atomic number but different mass numbers due to different number of neutrons.