Betty placed an unknown powder in a zip lock bag. When she added water to the bag, the powder bubbled, and it disappeared. When the bubbling stopped, the bag contained a clear liquid and a lot of gas.

What is the MOST OBVIOUS indicator a chemical reaction occurred?

(1 point)

A gas was formed.

There was a change in temperature.

The powder mixed with the water.

The powder changed color.

A gas was formed.