The correct answer is: by the transfer of one or more electrons from one atom to another.
Mass, if you know what element you are working with.
Answer: 0.4
Explanation: The easiest way to do this is to get a denominator of 10. To do this, multiply each number in 2/5 by 2. You will get the fraction 4/10. With the denominator of 10, the answer would be 0.4 by putting the decimal in front of the number.
