A scientist performed four investigations using eight different liquids. In each investigation, the scientist combined two of the liquids under a fume hood and recorded observations in the table below. Scientist’s Observations

Investigation

Observations After Two Liquids Are Combined

1

The temperature of the combined liquids increased, and a solid substance formed.

2

The temperature of the combined liquids decreased, and bubbles formed.

3

One liquid settled to the bottom of the beaker, and the other liquid rose to the top.

4

The combined liquids turned from clear to a bright purple.

In which investigation is it likely that the liquids reacted chemically?

Substance 1

Substance 2

Substance 3

Substance 4.