Water can act as either a base or an acid. Water acts as an acid by donating a hydrogen ion when it reacts with a stronger base such as sodium hydroxide. Water may also act as a base when it accepts hydrogen ion when reacting with a strong acid such as hydrochloric acid. This is based on Bronsted concept and definition of a base ( proton acceptor) and acid (proton donor). Such a compound that can act as a base and as an acid is called an amphiprotic molecule.
<span> Photosynthesis and cellular respiration are two major processes of carbon cycling in living organisms. A.) Both occur in animal and plant cells, Both include reactions that transform energy. 3) Both convert light energy into chemical energy.</span>
Answer:
Placebo, Is used to describe a substance given in clinical trial that does not contain the drug.
Explanation:
- Clinical trials are done to evaluate the effectiveness of a drug in treating a particular medical symptom or disease.
- In such case a placebo is used as a control in the experiment.
- A placebo contains all the components as the medicine except for the drug that is being tested.
- A placebo is given to one group of patients having the symptoms for which the drug is tested while another group of patients with same symptoms are given the drug.
- If the group that was given the drug show symptoms of cure while the group that was given placebo does not show changes. Then the drug is said to be effective.
Answer:
Independent variable: Adding/not adding soil.
Dependent variables: Does the plant grow? Amount of leaves, plant length.
Controlled variables: Type of plant used, amount of sunlight received, pot used for plant, amount of water given, temperature of soil, etc.
Explanation:
Independent variable: The thing that you want to change. To see if plants need soil to grow, you would need to either add or remove soil altogether.
Dependent variables: The thing that is being measured. By adding your independent variable, you should be able to answer certain questions.
Controlled variables: Things you want to keep the same for each experimental group. For example, if you used different plants, your results could be affected negatively as some plants might rely on soil less than others/grow at a slower or faster pace.
Answer: B
Explanation:
Evolution is a process of elimination. the traits that are successful and help them survive are kept for the next population, because they are abet o survive to repopulate. So its improvement.
