Answer:
A neutral particle made of an electron and hole
Explanation:
Exciton
It is the combination of an electron and a hole ( hole refers to the vacancy of an electron ) . And , as both the electron and the hole have the same charge but the polarity is opposite , the combination will lead to a neutral compound , i.e. , Exciton have no charge and so neutral .
It is free to move in the nonmetallic crystal and since it charge less , it is difficult to detect it directly .
Given :
An atom of a certain element has 12 protons, 14 neutrons, and 2 valence electrons.
To Find :
The name of this element.
Solution :
We know, element with atomic number ( number of protons ) 12 and valance electrons is Magnesium.
Now, isotope of magnesium of proton with 14 neutrons is Mg-16 .
Therefore, name of element is Mg-16 .
Hence, this is the required solution.
Answer:
= 13.0 moles O2
Explanation:
1] Given the equation: 2C8H18 + 25 O2 ----> 16CO2 + 18H2O
a. How many moles of oxygen gas are required to make 8.33 moles of carbon dioxide?
8.33 moles CO2 X
25mol O2
16mol CO2
= 13.0 moles O2
Cu(NO3)2>NO2+CuO+O2 balanced: 2Cu(NO3)2=4NO2+2CuO+O2
