There are two atoms that make up a single element
Answer:
relationships among organisms and evolutionary relationships for organisms with a shared common ancestor.
When tiny ice crystals in clouds stick together to form snowflakes, the result is snow. If enough crystals form a clump, they'll become heavy enough to fall to the ground. When temperatures are cold and moisture in the form of tiny ice crystals exists in the atmosphere, snow forms.
I believe that an adjuvant is a chemical addictive that increases the effectiveness of vaccines. It is a pharmacological or immunological agent that modifies the effect of other agents. It may be added to a vaccine to modify the immune response by boosting it such as to give a higher amount of antibodies and a longer lasting protection, and hence minimizing the amount of the foreign material or vaccine injected.
Answer:
Weather conditions
Explanation:
Food can be limited based on location, however, scientists can control what kind of food it is. Soil can be tested and experimented on. There can be a lot of it and different kinds. Space is fought over because of territories and is limited compared to how many people and animals there are. Weather is not something that can be controlled in an experiment since it is sporadic.