Answer:
1. 0.97 V
2. 
Explanation:
In this case, we can start with the <u>half-reactions</u>:


With this in mind we can <u>add the electrons</u>:
<u>Reduction</u>
<u>Oxidation</u>
The reduction potential values for each half-reaction are:
- 0.69 V
-1.66 V
In the aluminum half-reaction, we have an oxidation reaction, therefore we have to <u>flip</u> the reduction potential value:
+1.66 V
Finally, to calculate the overall potential we have to <u>add</u> the two values:
1.66 V - 0.69 V = <u>0.97 V</u>
For the second question, we have to keep in mind that in the cell notation we put the anode (the oxidation half-reaction) in the left and the cathode (the reduction half-reaction) in the right. Additionally, we have to use "//" for the salt bridge, therefore:

I hope it helps!
Its an element Im pretty sure
Answer:


Explanation:
Hola.
En este caso, para calcular la longitud (a) de una cara de celda unitaria, consideramos la siguiente ecuación:

En la que consideramos el número de átomos por celda (4 para FCC), la masa molar (40.3 g/mol para MgO) y el número de avogadro para obtener:

Despejando para a, obtenemos:
![a^3 = \frac{4atom/celda*40.3g/mol}{3.581g/cm^3*6.02x10^{23}atom/mol}\\\\a=\sqrt[3]{7.478cm^3} \\\\a=4.213cm](https://tex.z-dn.net/?f=a%5E3%20%3D%20%5Cfrac%7B4atom%2Fcelda%2A40.3g%2Fmol%7D%7B3.581g%2Fcm%5E3%2A6.02x10%5E%7B23%7Datom%2Fmol%7D%5C%5C%5C%5Ca%3D%5Csqrt%5B3%5D%7B7.478cm%5E3%7D%20%5C%5C%5C%5Ca%3D4.213cm)
Finalmente, el radio lo calculamos como:

¡Saludos!