No, that's not true. The center of the Earth is not a ball of gas. It's a solid ball of iron and nickel called the inner core.

Here's a breakdown of the Earth's structure:

* Crust: The thin, outermost layer of the Earth, where we live.

* Mantle: A thick layer of hot, solid rock that makes up most of the Earth's volume.

* Outer Core: A liquid layer of iron and nickel.

* Inner Core: A solid ball of iron and nickel, incredibly dense and hot due to immense pressure.

While the inner core is incredibly hot (around 5,200°C), it's solid because of the immense pressure from the layers above it.