Need help with the lap report

Observation and experimentation have led many scientists to accept a theory about the origin of the universe. this theory is called the big bang theory. scientific evidence collected and observed by scientists around the world suggests that the universe is ever expanding from a hot and dense initial state. what makes this a scientific theory? (2 points)

When the chemicals iron sulfide (fes) and hydrochloric acid (hcl) are combined, bubbles appear from the mixture. 1. does the appearance of bubbles indicate a physical or chemical change? 2. why do the bubbles indicate this change? 3. what property is this?

Iron (fe) reacts with copper sulfate (cuso4) to form iron (ii) sulfate. in this reaction, cu2+ gains electrons to form cu. which statement is true about this reaction? fe(s) + cuso4(aq) → feso4(aq) + cu(s)