-HELP-
How many molecules are contained in 125 grams of oxygen gas (O2)?

62.50

Explanation:

I divided the 125 in the result is 62.50 but it is considered a 62.

never mine:)

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e

in the analysis of systems that involve fluid flow, we frequently encounter the combination of properties u and pv.