1. There’s a steeple on top of the church.

A cross is on top of the steeple.


 2. A surfer rides his surfboard on top of the water.


 3. A clock and a statue are on top of the building.


 4. The nuts and chocolate on top of the ice cream taste really good.
ice cream

 5. A polar bear is standing on top of the ice and reaching underneath to grab a fish.

polar bear

 6. He has a helmet on top of his head.

("On" might be a better choice here. "He has a helment on his head," but some people will use "on top of" instead of "on."

man with helmet

 7. It’s a good idea to stay on top of the news.

stay on top of = monitor; watch; follow.