True or false? In a chemical reaction, energy may be gained or lost but the atoms stay the same

Although respiratory organs vary across different organisms, they all contain respiratory surfaces that have a large surface area and are extremely thin. explain why having an extremely thin respiratory surface with a large surface area is advantageous for the process of gas exchange

The missing component to the table to the right or indicated with orange letters complete the table by filling in the corresponding numbers or symbols

What is the percentage of hydrogen in c2h4