Question

how many neutrons are in nitrogen-15?
helium
2
he
4.0026
neon
10
ne
20.180
argon
18
ar
39.948
boron
5
b
10.811
carbon
6
c
12.011
nitrogen
7
n
14.007
oxygen
8
o
15.999
fluorine
9
f
18.998
aluminium
13
al
26.982
silicon
14
si
28.086
phosphorus
15
p
30.974
sulfur
16
s
32.065
chlorine
17
cl
35.453
8
15
7
6

Explanation:

Step1: Identify atomic number of nitrogen

From the periodic - table, the atomic number of nitrogen (N) is 7.

Step2: Recall the formula for calculating neutrons

The mass number (A) of an isotope is the sum of protons and neutrons. For nitrogen - 15, the mass number A = 15. The number of protons (p) is equal to the atomic number. So, the number of neutrons (n) can be calculated using the formula $n=A - p$.

Step3: Calculate the number of neutrons

Substitute A = 15 and p = 7 into the formula: $n=15 - 7=8$.

Answer:

8