what do these two changes have in common? a log decomposing in the woods salt and vinegar removing tarnish…

what do these two changes have in common? a log decomposing in the woods salt and vinegar removing tarnish from a penny select all that apply. both are changes of state. both are caused by heating. both are chemical changes. both conserve mass.
Answer
Brief Explanations:
- A log decomposing in the woods involves biological - chemical processes where organic matter is broken down by microorganisms, forming new substances.
- Salt and vinegar removing tarnish from a penny is a chemical reaction where the acidic vinegar and salt react with the copper - oxide (tarnish) on the penny to form new chemical compounds.
- Chemical changes involve the formation of new substances, and in both cases new substances are formed.
- According to the law of conservation of mass, in any chemical or physical change, mass is conserved. So both these chemical changes conserve mass.
- These are not changes of state (solid - liquid - gas transitions) and not caused by heating specifically.
Answer:
C. Both are chemical changes. D. Both conserve mass.