What does below science rebus mean?

Ag Ag Ag
Ag SPOON Ag
Ag Ag Ag

John was working on a Chemical Mixture whose weight comprise 90% liquid and 10% solid. The total weight of the mixture is 20 pounds. After a while, John noticed that some of the liquid evaporated and now the liquid comprises just 50% of the weight.

What is the weight of the chemical mixture now?

What can go up a chimney down, but can’t go down a chimney up?

The answer I give is yes, but what I mean is no. What was the question?

What is full of holes but still holds water?

If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?

If an earthquake is 1 point higher on the Richter Scale than another earthquake which is actually 10 times stronger, how much stronger would an earthquake be if it was just half a point higher on the Richter scale?

There is a five-letter word which has 3 consonants(all are same) and 2 different vowels.
Also, something wrong is associated with the word.

Can you name it?

When it's bad luck to meet a black cat?

Which country gets ill every time?