Venus is closer, relatively the same size as the earth and has an atmosphere
Well, electrons can be converted into a atomic number so if SE atomic number is 34 that means it has 34 electrons. AI has a atomic number of 13 meaning it has 13 electrons.
So the difference is that SE has more electrons then AI.
Hope this helped. :D
I think its Mercury because it's the closest to the sun.
Answer:
A star with 15 solar masses is too big to be a main-sequence star.
Answer:
Time period of the osculation will be 0.0671 sec
Explanation:
It is given a vertical spring is stretched by 4 cm
So change in length of the spring x = 4 cm = 0.04 m
Mass which is hung from it m = 12 gram = 0.012 kg
Sprig force will be equal to weight of the mass
So 

k = 244.7 N/m
Now new mass is m = 28 gram = 0.028 kg
So time period with new mass will be

