Ascientist is performing an experiment on a powder. which of the following is a sign that a chemical change has definitely occurred during his experiment?
the powder catches on fire
the powder bubbles
the power heats up
the powder brakes into small particles

there's the proffessional site that will you.

answer: ice crystals in air

the water from the water body or another source of water gets evaporated as water vapor as an effect of heat on water. these water vapor rises in the upper layers of the earth atmosphere under high atmospheric pressure. the atmospheric pressure of these water molecules starts to decrease due to the effect of cold air. the invisible water vapor condenses into visible water droplets and ice crystals.these ice crystals and water droplets being less denser than the surrounding air floats on air as clouds.

my teacher would say no s