Answer:
c or b
Explanation:
the story is entertaining and it shares the teachers personal experiences with the teachers students
A. Adding a catalyst. A catalyst by definition is a compound that speeds up reaction rates.
Answer:
It represents the <em>number of atoms</em> of that particular element present in the compound. In C₂H₄O₂ there are 2 Carbon atoms, 4 Hydrogen atoms and 2 Oxygen atoms.
Answer:
This is a chemical change because it has been lit on fire. When it is lit on fire, the fire has been made, heat has been made, and gasses produced from the fire have also been made. Because this introduces new matter to the pictures, it is a chemical reaction.
Explanation:
The sun generates its energy by nuclear fusion of hydrogen nuclei into helium.
