Math
posted by Nicole .
(This is just an example)
A proton has a size of 1.23x10^11 and an electron has a size of 1.4x10^8. How many times smaller is and electron than a proton?
Now the part I need help with the which scientific notation goes in the numerator? Is it 1.23x10^11 or the 1.4x10^8?

This means: how many times larger is a proton then an electron?
Thus we put the proton on the numerator and the electron on the denominator.
From pure chemical science, a proton is wayyy bigger (and heavier) than an electron. Thus, if you get an answer that is really small then you know you are wrong. 
Okay thank you. But would 0.000000000123 be 1.23x10^11?

Actually, that would be 1.23 x 10^10. Move it over one more place. Count 11 places from 1.23. From 1.23 to 0.123 there is one jump.

Would that mean that my answer would be 0.88x10^18?