Answer : The concentration of 
ion is, 
Solution : Given,
pH = 4.20
First we have to calculate the pOH.
As we know that,
Now we have to calculate the concentration of ion.
![pOH=-\log [OH^-]](https://tex.z-dn.net/?f=pOH%3D-%5Clog%20%5BOH%5E-%5D)
![9.8=-\log [OH^-]](https://tex.z-dn.net/?f=9.8%3D-%5Clog%20%5BOH%5E-%5D)
![[OH^-]=1.58\times 10^{-10}M](https://tex.z-dn.net/?f=%5BOH%5E-%5D%3D1.58%5Ctimes%2010%5E%7B-10%7DM)
Therefore, the concentration of ion is,
A physical change that may happen in a movie theater is:
You accidentally step on a piece of popcorn.
That piece of popcorn is still made up of the same things but LOOKS different. Therefore, the piece of popcorn went through a physical change.
I hope this helps!
The answer depends on what substances you were testing, but here are some ideas.
If all of them were white as in the typical experiment, then color is not very useful. If you were allowed to taste them, then a salty taste would be a helpful clue. If the textures were different, some crystals, like salt or sugar and others powdery, like flour or cornstarch, those properties would be helpful. If some dissolved in water,...
Answer:
The chlorine atom (or atoms) is covalently bonded by a shared pair of electrons to the other element.
Explanation:
