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 .
Density gives mass of object per volume...... Here, density is given 8.90 g/cm3 therefore, per cubic centimeter contains 8.90 g Ni. mole of Ni = mass / atomic mass = 8.90 / 58.6934 = 0.1516 mole number of atoms: mole * 6.022 * 10^23 = 0.1516 * 6.022 * 10^23 = 0.9129 * 10^23 = 0.9 * 10^23 (approx.)
I believe it’s a positive charge
Answer:
4
Explanation:
bromothymol blue turns yellow betwwen then pH levels of 2 and 6
Given :
Length , l = 59.8 m.
Breadth , b = 26.6 m.
Depth , d = 3.7 ft .
Density of water , .
To Find :
Mass of water in pool .
Solution :
First we will covert depth into m from ft .
For ,
So , volume of pool is :
We know , density is given by :
So ,
Putting given values in above equation :
Hence , this is the required solution.