00:01
Hi, in this question, in the first part of the question, we have to find the number of electrons.
00:05
So, here we are given with first part that is a part.
00:08
We are given with the charges.
00:11
So, we are given with q is equal to 1 coulomb and e is equal to 1 .6 into 10 power minus 19 coulomb.
00:17
So, q is equal to n into e.
00:19
So, n will be equal to q by e.
00:21
So, i am substituting the values we have.
00:23
So, for case a, we have n is equal to so 1 divided by 1 .6 into 10 power minus 19.
00:31
So, that is equal to 6 .25 into 10 power 18.
00:35
Then we have so for second case, so for case b, so neglecting the magnitude, we have again n is 6 .25 into 10 power 18 charges and for part c, we have q as minus 1 .6 into 10 power minus 6 coulomb.
00:53
So, neglecting the negative sign, we have n will be equal to 1 .6 into 10 power minus 6 divided by 1 .6 into 10 power minus 19.
01:03
So, from this we have n is equal to 3, 10 power.
01:08
So, n is equal to 10 power 13.
01:10
So, this is the first part.
01:12
In the second part of the question, we have given with the value of q as 4 .5 into 10 power minus 7 coulomb.
01:17
So, we have the positive electron will be equal to 1 .6 into 10 power minus 19 coulomb and negative electron will be 1 .6 into 10 power minus 19 coulomb.
01:28
Then we have the net electron is equal to it is in p into qp plus ne into qe.
01:35
So, we have to find so np divided by ne is equal to q divided by so q divided by e.
01:43
So, that is equal to we have 1 .5 into 10 power minus 7 divided by 1 .6 into 10 power minus 19.
01:50
So, the mass number of proton will be equal to 2 .81 into 10 power 12 more than the electron.
01:57
So, greater than the mass of electron.
02:01
Then we have for case b, we have q minus q dash is given as 0.
02:06
So, this implies q dash will be equal to q is equal to 4 .5 into 10 power minus 7 coulomb.
02:12
So, we have np is equal to so np can be given by this is q dash divided by qp which is equal to so 4 .5 into 10 power minus 7 divided by 1 .6 into 10 power minus 19 which is equal to 2 .81 into 10 power 12.
02:30
Then we have mass of the electron is known mass of the proton is known.
02:34
Therefore, m is equal to mp into np that is equal to so 1 .67 into 10 power minus 27 into 2 .81 into 10 power 11...