Calculate the number of neutrons in 14N7 -3ions
Answers
Answer:
Nitrogen-14 is actually an isotope of nitrogen, so right from the start, you can say that it is a neutral atom.
Isotopes are atoms that have the same number of protons but different numbers of neutrons in the nucleus. You know that nitrogen-14 has
7
protons in the nucleus because it is an isotope of nitrogen, which has an atomic number equal to
7
.
Because nitrogen-14 is a neutral atom, the number of protons it has in its nucleus must be equal to the number of electrons that surround its nucleus.
neutral atom
⇒
no. of protons = no. of electrons
Now, in order to find the number of neutrons present in the nucleus of a nitrogen-14 atom, you must use its mass number. The mass number of an isotope is added to the name of the isotope.
In this case, you have
nitrogen-
14
⇒
mass number
=
14
The mass number of an atom tells you the number of protons and neutrons located in the nucleus.
So you can say that
no. of protons + no. of neutrons
=
14
This implies that a nitrogen-14 atom contains
(
14
.
protons + neutrons
)
−
7 protons
=
7 neutrons
Now, a nitrogen atom, regardless of its mass number, will always form
3
−
anions,
N
3
−
. In other words, any nitrogen atom will take in
3
electrons to complete its octet--this happens because nitrogen is located in group
15
of the Periodic Table.