atomic structure

Two carbon discs of 1.0 g each are 1.0 cm apart have equal and opposite charges. If forces of attraction between them is 1.0*10-5 N.
calculate the ratio of excess electrons to total atom on the negatively charged disc.
(permittivity constant is 9.0*109 Nm2c-2)

6 Answers

62
Lokesh Verma ·

first find q

then divide by charge of electron to find the no of charged particles

then total no of atoms is given by no of moles of C x avogadro's number

no of moles is 1/12

I hope this out line helps

1
skygirl ·

neither cud i get the question nor its solution...

uff mind jammed :'(

62
Lokesh Verma ·

did u get the solution mona?

11
mona100 ·

sir
as per your solution i am getting q=3*10-9
excess electrons =1.8*1010
total no. of atoms= 5*1022
so the answer i am getting is=3.7*10-13

and the correct answer given is 4.17*10-14

plz check my solution

62
Lokesh Verma ·

Two carbon discs of 1.0 g each are 1.0 cm apart have equal and opposite charges. If forces of attraction between them is 1.0*10-5 N.
calculate the ratio of excess electrons to total atom on the negatively charged disc.
(permittivity constant is 9.0*109 Nm2c-2)

kQ2/r2= 10-5

kQ2/r2= 10-5

9.109Q2=10-5.10-4

Q2=10-18/9

Q=10-9/3

so your answer will get divided by 9 :)

11
mona100 ·

thank u sir i now got it
such a sily mistake.....

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