What does below chemistry rebus means?

What does this Rebus Picture means ?

I am a type of vehicle that has two wheels and is powered by humans. What am I?
Hint 1: You can ride me for exercise.
Hint 2: I am environment-friendly.

On a charity event in Russia, Murray beat Djokovic by winning six games and losing three games.
Note: There is a total of 5 service breaks(one who serve lost the game).
Who served first, Djokovic or Murray?

Can you identify the famous TV character from the rebus below?

What occurs twice in a week, once in a year but never in a day?

What jumps when it walks and sits when it stands?

The day before yesterday I was 25 and the next year I will be 28. This is true only one day in a year. What day is my birthday?

Four people need to cross a rickety bridge at night. Unfortunately, they have only one torch and the bridge is too dangerous to cross without one. The bridge is only strong enough to support two people at a time. Not all people take the same time to cross the bridge. Times for each person: 1 min, 2 mins, 7 mins and 10 mins. What is the shortest time needed for all four of them to cross the bridge?

Can you count the number of triangles inside a triangle?