What does below chemistry rebus means?

What has 88 keys?

Can you replace the question mark with the correct number in the below table sequence?

It has horns but can’t beep. It is like to bleat but It is not a sheep. What is it?

They came out at night, without being called.
They lost at day, without being stolen.
Who are they?

You need to complete the maze by entering from the entrance marked below in the figure near the yellow circle, bottom left and leaving from the exit point near the green circle, bottom middle.

Rule of Game: You can move only by exchanging green and yellow circles.

Can you find the missing piece of the Porsche?

What has 13 hearts but no other organs?

You have to fill the below given grid in a manner that every row and column contains the digits 1 to 6. Also, make sure that the squares that are connected with each other must contains the same digit.

There is something which you can be arrested for attempting but not for successfully completing.