# How many number in one-fifth?

one-fifth = 1/5 as a fraction or 0.2 as a decimal

### Why is it not possible for an atom to have an atomic number less than the atomic mass?

The atomic number of an element is how many protons that element has, then you have to take in how many neutrons it has then add that together to get you mass number. The mass number is how many protons+neutrons you have i an element, and the atomic number is how many protons you have in an atom. But the Atomic Mass is the average of the normal elements Atomic number+ the elements isotopes atomic…

### How many neutrons are in magnesium-25?

The "25" is the mass number, which is the sum of the number of neutrons and protons. We don't know how many neutrons there are, but we do know how many protons magnesium has. The atomic number of an element is the same as the number of protons, so locating a periodic table, magnesium is number 12, which means 12 protons. If mass number = number of protons + number of neutrons, then number of…

### What is next decimal number of the number 65?

There is no such thing as a "next" decimal number. Numbers are infinitely dense: that is, between any two numbers there are infinitely many numbers. Therefore, given any number claiming to be next after 65, there are infinitely many numbers between 65 and that number - The smallest of these has a better claim at being next. But there are infinitely many numbers between 65 and this number. There is no such thing as a…