Answer: Thus the correct option is D. All of the above describe a mole
Explanation:
According to avogadro's law, 1 mole of every substance weighs equal to molecular mass in grams.
1 mole of every substance contains avogadro's number of particles.
Mole is the S.I unit for measuring the amount of substance. It is often used to measure large number of particles.
Thus the correct option is D. All of the above describe a mole
1) Drift velocity:
2) electrons per person
Explanation:
1)
For a current flowing through a conductor, the drift velocity of the electrons is given by the equation:
where
I is the current
n is the concentration of free electrons
is the electron charge
A is the cross-sectional area of the wire
The cross-sectional area can be written as
where r is the radius of the wire. So the equation becomes
In this problem, we have:
I = 8.0 A is the current
is the concentration of free electrons
d = 1.5 mm is the diameter, so the radius is
r = 1.5/2 = 0.75 mm =
Therefore, the drift velocity is:
2)
The total length of the cord in this problem is
L = 3.00 m
While the cross-sectional area is
Therefore, the volume of the cord is
(1)
The number of electrons per unit volume is , so the total number of electrons in this cord is
In total, the Earth population consists of 8 billion people, which is
Therefore, the number of electrons that each person would get is: