how many neutrons are in an atom ?

Answer 1

It depends on the atom. A hydrogen atom usually has zero, but it can also have one or two. A uranium atom can have as many as 146.

Answer 2

Take the Atomic number from the Atomic Weight.

The Atomic Number is the number of Protons

The Atomic Weight is the number of Protons + the number of Neutrons.

Example:

Tin (Sn) has an Atomic Weight of 119 and an Atomic No. of 50

As above: Atomic Wt. - Atomic No. = 119 - 50 = 69

Therefore the number of Neutrons in the nucleus of Sn = 69.

(Incidentally, the number of Electrons is equal to the number of Protons ... Electron mass is considered negligible at 1/1840th that of a proton).

The Periodic Table will give you the details you need to perform these calculations for any Element.

Answer 3

Generally, the number of neutrons can be found by subtracting the atomic number (number of protons) from the atomic mass (this is an average number of protons plus neutrons found in the atom). However, the atomic mass is generally a decimal, and there cannot be fractions of neutrons. This is because there are various isotopes of each atom found in nature. An isotope is a version of an atom, but has a different number of neutrons from another isotope. Otherwise, the rest is the same. However, this affects the atomic mass. The average mass, as shown on periodic tables, is calculated by taking the average masses of the various isotopes of each atom found in nature and finding an average mass in relations to how common each isotope is in nature. Hope I could help!

Answer 4

Different atoms have different numbers. A common hydrogen atom, for example, has none: the nucleus contains just one proton. If there is a neutron along with that one proton, then you have an "isotope" of hydrogen called Deuterium.

If you google "periodic table" you'll see how each element contains a different number of protons and neutrons. Oxygen has 8 of each, if remember my chemistry....

Answer 5

Depends which atom.

Generally, the number of Neutrons in an atom equals the atomic weight - the atomic number.

ie: Carbon,C
has an atomic weight of 12
and atomic number 6

so it has 12- 6 = 6 neutrons

Answer 6

Basically, it depends on the element, find a periodic table of elements to know which element has which amount of neutrons. I think they will usually have the same amount of neutrons as protons.