Thanks alot, mum_sugoku! I appreciate your help!

My DS has another question on electrochemistry.


Why must the electrolyte be Copper(II)Sulphate solution for the purification of copper? Can’t it be other molten or aqueous ionic compounds?

Thank you.

My DS still has another question on lens.


When light which is perpendicular to the principal axis passes through a converging lens, what happens to its path?

I would appreciate if anyone can enlighten me again.

Thanks everyone for contributing their replies!


My doubts are cleared for now!

My DS has a physics question. It is on the topic of light.


Converging lens A & B have the same focal length, but B is only half the diameter of A. Both lenses are used to form the images of distant objects on a screen. Which of the statement is correct?

A. For both lenses, the distances from the lens to the screen is the same.
B. For both lenses, the images are of the same brightness.
C. For both lenses, the images are the same size as the object.
D. Lens B gives a smaller image than A.

The correct answer is C, but my DS still do not understand. May anyone enlighten us?

Thank you Selfan4ever23 & bestwishes for your replies!

I have an question on the method of reproduction from my son’s exercise.


x - Man, Frog, Polar bear\t\t
y - Yeast, Amoeba, Paramecium
\t
a)What is the main difference between the two methods of reproduction for X & Y?
b)Name the reproduction method under the sub-heading X.