Question

Please help when an electric current is passed through water during the process of electrolysis, two gases are formed. One gas has a boiling point of -183C degree and the other has a boiling point of -253C degree. Has a physical or chemical change occurred?

Answer 1

I'm not absolutely positively sure of this.  I'm only about 99.5% sure.
I'm going to say that it's a chemical change.

Why ?

When a physical change occurs, the properties and characteristics of
the substance stay the same ... like crushing a rock, or boiling water.

In this experiment, you started with water.  Water is a single substance,
and its boiling point is +100°C.

After the change, you suddenly have TWO substances.
Their boiling points are  -183°C  and  -253°C  .

It's plain to see that the characteristics and properties of the
new substances are nothing like the original substance.

Yep.  I convinced myself.  It's definitely a chemical change.