Answer:
The signs of chemical change include changes in color, temperature, the production of light, changes in odor, and the formation of gases.
1st one is Science and the 2nd one is Bias
The reaction, Fe2O3 + 3CO------> 2Fe + 3CO2 is an oxidation-reduction reaction.
An oxidation-reduction reaction is a reaction in which there is a change in oxidation number from left to right in the reaction. This is because, a specie is oxidized and another specie is reduced.
In the reaction; Fe2O3 + 3CO------> 2Fe + 3CO2, we can see that the oxidation number of iron decreased from +3 on the left hand side to zero on the right hand side. The oxidation number of carbon was increased from + 2 to +4.
Learn more: brainly.com/question/10079361
Isotopes of elements have same atomic numbers and different mass number(atomic masses).
