1 â¢ Ozone (O3) is an extremely reactive gas molecule composed of three oxygen atoms. â¢ 2  Ozone forms in chemical reactions in the atmosphere when nitrogen oxides (NOx) and volatile organic compounds (VOCs), also called hydrocarbons (HC), come into contact with both sunlight and heat. â¢ Ozone (O3) is an extremely reactive gas molecule composed of three oxygen atoms. â¢ 2  Ozone forms in chemical reactions in the atmosphere when nitrogen oxides (NOx) and volatile organic compounds (VOCs), also called hydrocarbons (HC), come into contact with both sunlight and heat.
Grolar bears. The offspring of a grizzly bear and a polar bear, a grolar bear is one beast you don't want to meet in the woods. Interestingly, unlike many hybrid animals on this list, grolar bears are known to occur naturally in the wild.
The best indicators are the size of the shoulders, the profile of the face and the length of the claws. The grizzly bear has a pronounced shoulder hump, which the black bear lacks. It also has a concave or âdishedâ facial profile, smaller ears and much larger claws than the black bear. Black bears have a flatter, âRoman-noseâ profile, larger ears, no visible shoulder hump and smaller claws. Click here for more information on the physical differences between black bears and grizzly bears.