Neutrons and Protons are equal in mass (≈ 1amu)
<h2>Answer and Explanation </h2>
Nitrogen is present in group 5. It contains 7 electrons and protons. It has 2 electrons in its first shell and 5 electrons in second shell. In order to determine the atomic number of nitrogen, we should know about the number of protons or electrons of the atom.
Atomic number is denoted by Z. Z= number of protons. Hence, nitrogen consists of seven protons as well as seven electrons. Therefore, its atomic number (Z) will also be 7.
Answer:
a. First order.
b. 
c. 
d. ![[A]=0.111M](https://tex.z-dn.net/?f=%5BA%5D%3D0.111M)
Explanation:
Hello.
a. In this case since the slope is in s⁻¹ we can infer that the lineal form of the rate law is:
![ln[A]=-kt+ln[A]_0](https://tex.z-dn.net/?f=ln%5BA%5D%3D-kt%2Bln%5BA%5D_0)
Which is also:

It means that the reaction is first-order as slope equals the negative of the rate constant which also has units of first-oder reaction.
b. Since the slope is −3.7 x 10−3 s−1 the rate constant is:

c. For first-order reactions, the half-life is:

d. In this case, since the integrated first-order rate law is:
![[A]=[A]_0exp(-kt)](https://tex.z-dn.net/?f=%5BA%5D%3D%5BA%5D_0exp%28-kt%29)
The concentration once 220 seconds have passed is:
![[A]=0.250Mexp(-3.7x10^{-3}s^{-1}*220s)\\\\](https://tex.z-dn.net/?f=%5BA%5D%3D0.250Mexp%28-3.7x10%5E%7B-3%7Ds%5E%7B-1%7D%2A220s%29%5C%5C%5C%5C)
![[A]=0.111M](https://tex.z-dn.net/?f=%5BA%5D%3D0.111M)
Regards.