When? Mars and Earth are constantly moving, so the distance between them is constantly changing. If you're really interested, it would be trivial to look up their relative distances from the sun, and figure out how far apart they can ever be (if they're both on opposite sides of the sun) or how close they can ever get (if they're both on the same side of the sun).
I'm not going to do that for you, though, because I would hate to spoil your joy of discovery.
It is: 1.277*10^6 in scientific notation
100 million in Scientific Notation = 1 x 108
I believe you mean scientific notation. 0.0000547 in scientific notation is 5.47 x 10-5.
2.5 mcg in Scientific Notation = 2.5 x 100mcg
Mercury has a radius of 2439.5km. In scientific notation, this would be 2.4x103km.
38 meters
The average distance between Earth and Mars is about 225 million kilometers. In scientific notation, this distance is approximately 2.25 x 10^8 kilometers.
.0000000001
It depends on the way in which it is written!
It's not necessary to put numbers of this size into scientific notation but if you really have to, go with 4.125 x 10^0
It's not necessary to put numbers of this size into scientific notation but if you really have to, go with 4.215 x 10^0
Planet Mars has a mass of 639 x 1021 kilograms (639,000,000,000,000,000,000,000kg)
0.00001276 meters in Scientific Notation = 1.276 x 10-5 meters.
A proton is 2x10^-14m, or 0.00000000000002m
Proxima Centauri is a star and there is no scientific notation for a star. There will be scientific notations for the values of its distance, its size, its age, luminosity, magnitude and so on but the question is not about any of them!
Only if the numbers to be converted into scientific notation are the same otherwise the exponents can vary according to the size the numbers.
It is 8.9*10^-5 in scientific notation