Answer:
A. atomic number
Explanation:
the mass number alone cannot uniquely identify an element. But the number of protons in the nucleus identifies it uniquely. In addition, if the atom is neutral, then the atomic number also equals the number of electrons in its orbitals.
Answer:
valence electrons are the ones
23. The atomic mass is calculated by adding the number of protons and neutrons. However, you cannot guess the number of neutrons. Refer to the periodic table. The atomic mass/mass no of Sodium is 23.
Answer:
1.1 M
Explanation:
The dissociation of
is as follows:

Given Value for 
The equation for the reaction for the formation of complex ion
is :

The value of 
If we combine both equation and find the overall equilibrium constant will be:


<u> </u>



If
= x M
The solubility of
in the
solution will be:


Constructing an ICE Table; we have :

Initial (M) x 0 0
Change (M) -2 (0.0518) + 0.0518 + 0.0518
Equilibrium (M) x - 0.1156 0.0518 0.0518
Equilibrium constant;
(K) = ![\frac{[Ag(NH_3)_2^+][Cl^-]}{[NH_3]^2}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BAg%28NH_3%29_2%5E%2B%5D%5BCl%5E-%5D%7D%7B%5BNH_3%5D%5E2%7D)



x = [NH₃] = 1.089 M
[NH₃] ≅ 1.1 M
The maximum number of electrons that an energy level can hold is determined from the formula 2n^2 equals the total number, where n is the energy level. The first energy level holds 2*1^2=2 electrons while the second holds 2*2^2= 8 electrons.