To be fair, Hydrogen-1 not decaying would give you an infinite half life, which is the longest you could get.
Also, this is a few more sciences than chemistry. Photosynthesis, while being a chemical reaction, does fall into biology as it is a natural reaction performed by living organisms frequently. The model of the atom falls into physics, and while Marie Curie did discover two elements, that falls into history. Chemistry is defined as "the branch of science that deals with the identification of the substances of which matter is composed; the investigation of their properties and the ways in which they interact, combine, and change; and the use of these processes to form new substances." This is specifically referring to ELEMENTS and MOLECULES.
Beyond that, why does a dear lady have claws? Dear have cloven hooves... not sure if this was intended or just art not coming over well. Animation was top quality, and the rest of the art was fairly well done.