question 4 options:
The correct formula is the first one.
Copper has two valences I and II, in this example, it's mentioned that copper's valence is I.
Then we have to look in all the formulas for one formula where copper has that valence, and that valence is in formula 1 and 3. Number 4 is discarted that formula is incorrect, that formula doesn't exist.
Number 2 is also discarted because in this formula Cu has a valence of 2.
Number three is discarted because here Bromide has a valence of 2 and that is incorrect, Bromide's valence is 1.
The answer would be D, when the plastic strip and cloth are rubbed together there is a transfer of electrons from the plastic strip to the cloth leaving the plastic strip positively charged as it lost electrons, while the cloth becomes negatively charged.
yea some data is shown what is the question dude