I. Each carbon atom can form single bonds with up to four other carbon atoms. II. Each carbon atom can form double bonds with up to two other carbon atoms. III. Carbon atoms can join together to form chains or rings. IV. A single molecule of some compounds can contain thousands of carbon atoms.
Answer:
All the given choices
Explanation:
Carbon is a very interesting element which is the backbone of most organic compounds.
Organic compounds are made up of carbon. Carbon forms a wide range of compound due to the following properties;
- An atom of carbon has 4 valence electrons and can bond with 4 other carbon.
- Carbon can form single, double and triple covalent bonds.
- They can join together to form rings or chains.
A is the answer
Training programs for animal control officers usually take from a few weeks to a few months to complete.
The first step the biologist needs to make an observation in which to create a hypothesis.
Hope this was helpful!
Read more on Brainly -
brainly.com/sf/question/1687984
Answer:
immune system
Explanation:
The adaptive immune system reacts specifically to pathogens (germs). It is able to recognize attacking pathogens and fights against certain antigens or foreign substances. The next time a known antigen is encountered, the adaptive immune system can respond faster.