Answer:
"Endothermic reaction: In an endothermic reaction, the products are higher in energy than the reactants. Therefore, the change in enthalpy is positive, and heat is absorbed from the surroundings of the reaction."
Explanation:
Soil is made from dead plants, animals, and rocks.
Answer : Al
Explanation :
- For a given redox reaction there must be an oxidizing agent/(s) and a reducing agent/(s).
- the oxidizing agent is the substance that undergoes reduction process (gaining electrons or loss of oxygen atoms), meanwhile, the reducing agent is the substance that undergoes oxidation process (loss of electrons or gaining of oxygen atoms).
- In the reaction above, the oxidation number of (Al) in AlCl3 is (3+). However, the oxidation number of (Al) in the products is zero because it exists as a single element.
Therefore, changing from (3+) to zero means gaining of (3) electrons to neutralize the previously existing (3) protons on (Al) in AlCl3.
So Al is the oxidizing agent..
Physical changes are changes that change the physical traits of the substance, without making any change in their internal structure. Chemical changes effect internal structure of the substance and new substance is formed.
Examples of physical changes - breaking glass, evaporating alcohol, shredding paper...
Chemical : burning paper, heating sugar to form caramel, rusting of iron...
