<span>A, b, y c son cambios físicos. D es un cambio químico.</span>
Answer:5.5673
Explanation: I searched it up for you
C) why because it’s says 320 cL wich means that.....
Answer:
The volume of HCl required is 
Explanation:
From the question we are told that
The chemical equation for this reaction is

The mass of Al is 
The concentration of HCl is 
The number of moles of
given is 
The molar mass of Al is 
So


From the balanced equation
2 moles of Al reacts with 6 moles of HCl
So 0.07 moles of Al will react with x
Therefore


Now the volume of HCl can be obtained as

So 

Answer:
Co = 1s2 2s2 2p6 3s2 3p6 4s2 3d7
Explanation:
Number of electrons = 27
The closest noble gas before cobalt is Argon and argon has 18 electrons.
Co = [Ar] ; Remains 27 - 18 = 9 more electrons to fill.
The next orbital in order of increasing energy is the 4s orbital. However it can only hold a maximum of 2 electrons.
We have;
Co = [Ar] 4s2; Remains 27 - 20 = 7 more electrons to fill.
The next orbital in order of increasing energy is the 3d orbital. It can have a maximum of 10 electrons.
So we have;
Co = [Ar] 4s2 3d7
The electronic configuration of Ar = 1s2 2s2 2p6 3s2 3p6
This means the entire configuration of cobalt is;
Co = 1s2 2s2 2p6 3s2 3p6 4s2 3d7