Answer:
a solution color becoming less intense due to dilution- is not an evidence of a chemical reaction
bubbles (gas formation) - evidence of a chemical reaction
explosion or fire - evidence of a chemical reaction
changes in color- evidence of a chemical reaction
precipitation- evidence of a chemical reaction
changes in temperature - evidence of a chemical reaction
a solid liquifying - is not an evidence of a chemical reaction
solution colors mixing - is not an evidence of a chemical reaction
Explanation:
A chemical change is not easily reversible and yields new substances. It is often accompanied by a loss or gain of heat.
In the answer section, i have shown some evidences that lead us to conclude that a chemical reaction has taken place. The occurrence of a chemical change often goes with the formation of new substances as earlier stated and any of these signs may accompany the process.
For instance, when a metal is dropped in dilute acid solution, bubble of hydrogen gas indicates that a chemical reaction has taken place.
Answer:
Both answer choice 2 and answer choice 3 are correct choices.
Explanation:
Biotic factors are living components in an ecosystem. They are living organisms which affect another living component in an ecosystem.
Antibiotic factors are non living components of an ecosystem. They are chemicals which affect living organisms.
The choice 2 is correct. The seeds spread out by mice is a biotic factor interacting with an antibiotic factor
Choice 3 is correct. The seeds in the soil grow into new trees are biotic factors interacting with an antibiotic factor
Nucleic Acids are polymers made of nucleotideds
Sulfide would be an AWNSER but