In a neutral atom, the number of protons is equal to the number of electrons.
Given that the charge on the ion of the element is -1. This means that there is one electron more than the number of protons in the element.
The atomic number = Number of protons = 57 -1 = 56
Element with atomic number 56 is Barium.
Mass number of the element = Number of protons + Number of neutrons
= 56 + 80 = 136
So the identity of the species:
Answer:
The answer to your question is d. 0.5 M
Explanation:
Data
[A] = 1M
K = 0.5
Concentration of B and C at equilibrium = x
Concentration of A at equilibrium = 1 - x
Equation of equilibrium
k =
Substitution
Simplification
0.5 =
Solve for x
0.5(1 - x) = x²
0.5 - 0.5x = x²
x² + 0.5x - 0.5 = 0
Find the roots x₁ = 0.5 x₂ = -1
There are no negative concentrations so the concentration of A at equilibrium is
[A] = 1 - 0.5
= 0.5 M