Answer:
Strontium
Explanation:
The atomic number of strontium is 38.
It has 38 electrons.
It is alkaline earth metal. It has two valance electrons.
Strontium loses its two electrons and form cation with +2 charge.
Electronic configuration;
Sr₃₈ = [Kr] 5s²
The valance electrons present in 5s are lost by strontium atom and form Sr⁺² cation.
it is yellowish-white metal.
It is highly reactive.
It form salt with halogens.e.g
Sr + Br₂ → SrBr₂
IT react with oxygen and form oxide.
2Sr + O₂ → 2SrO
this oxide form hydroxide when react with water,
SrO + H₂O → Sr(OH)₂
With nitrogen it produced nitride,
3Sr + N₂ → Sr₃N₂
With acid like HCl,
Sr + 2HCl → SrCl₂ + H₂
5480milligrams=5.47×10^1grams
5480×10^-2
5.480×10^(-2+3)
5.48×10^1grams
<u>Answer:</u> The pH of the solution is 11.24
<u>Explanation:</u>
We are given:
Molarity of ammonia = 0.2 M
The given chemical equation follows:
I: 0.2
C: -x +x +x
E: 0.2-x x x
The expression for equilibrium constant follows:
![K_b=\frac{[NH_4^+][OH^-]}{[NH_3]}](https://tex.z-dn.net/?f=K_b%3D%5Cfrac%7B%5BNH_4%5E%2B%5D%5BOH%5E-%5D%7D%7B%5BNH_3%5D%7D)
Putting values in above expression, we get:
Neglecting the negative value of x as concentration cannot be negative.
So, ![[OH^-]=x=1.88\times 10^{-3}M](https://tex.z-dn.net/?f=%5BOH%5E-%5D%3Dx%3D1.88%5Ctimes%2010%5E%7B-3%7DM)
pOH is defined as the negative logarithm of hydroxide ion concentration present in the solution.
![pOH=-\log [OH^-]](https://tex.z-dn.net/?f=pOH%3D-%5Clog%20%5BOH%5E-%5D)
Putting values in above equation, we get:
We know:
Hence, the pH of the solution is 11.24
Answer:
its true i just looked on quizlet
Explanation:
His revisions proved the importance of the atomic number and acknowledged why some of the elements seemed like they were out of place, even though they were in the right place.
