What does the below rebus riddle means?

Look at me. I can bring a smile to your face, A tear to your eye, Or even a thought to your mind. But, I can't be seen. What am I?

Through your logical capabilities, can you make 7 an even?

Can you solve the rebus below?

Mr Black, Mr Gray, and Mr White are fighting in a truel. They each get a gun and take turns shooting at each other until only one person is left. Mr Black, who hits his shot 1/3 of the time, gets to shoot first. Mr Gray, who hits his shot 2/3 of the time, gets to shoot next, assuming he is still alive. Mr White, who hits his shot all the time, shoots next, assuming he is also alive. The cycle repeats. If you are Mr Black, where should you shoot first for the highest chance of survival?

What makes this number unique: 8,549,176,320?

Before Balboa discovered the Pacific Ocean, which was the largest ocean before that?

What has one eye, but can’t see?

Can you think of any three-dimensional shape that comprises of exactly two surfaces?

This puzzle is for Harry Potter fans. Do you know why Tom Riddle is called Lord Voldemort?