Answer:
option A is correct ( sodium, calcium and barium)
Explanation:
Given compounds:
Sodium chloride , calcium sulfide, barium oxide
We know that metals form positive ions. In order to solve the problem we must identify the metals from given compounds.
Na⁺Cl⁻
Ca²⁺S²⁻
Ba²⁺O²⁻
We can see that sodium, calcium and barium contain positive charges.
Thus option A is correct.
Because sodium have one valance electron. When it combine with chlorine sodium lose its one electron to complete the octet and chlorine accept it to complete its octet. Thus sodium form positive ion and chlorine form negative ion.
Similarly barium and calcium are present in group 2. Both have two valance electron. When they lose them cation are formed.
Other option are incorrect because,
Option B have sulfur and oxygen which are anion.
Option C have chlorine which is also anion
Option D have chlorine, sulfur and oxygen that are anions.
Answer:
r = 3.61x
M/s
Explanation:
The rate of disappearance (r) is given by the multiplication of the concentrations of the reagents, each one raised of the coefficient of the reaction.
r = k.![[S2O2^{-8} ]^{x} x [I^{-} ]^{y}](https://tex.z-dn.net/?f=%5BS2O2%5E%7B-8%7D%20%5D%5E%7Bx%7D%20x%20%5BI%5E%7B-%7D%20%5D%5E%7By%7D)
K is the constant of the reaction, and doesn't depends on the concentrations. First, let's find the coefficients x and y. Let's use the first and the second experiments, and lets divide 1º by 2º :
x = 1
Now, to find the coefficient y let's do the same for the experiments 1 and 3:
y = 1
Now, we need to calculate the constant k in whatever experiment. Using the first :
k = 4.01x10^{-3} M^{-1}s^{-1}[/tex]
Using the data given,
r = 
r = 3.61x M/s
Electron structure of sodium:
₁₁Na: 1s²2s²2p⁶3s¹
The answer should be false. Elements contain only one atom.
