Answer:
1) Liquid hydrogen has the lowest density of any liquid.
2) Hydrogen is the chemical element with the symbol H.
3) Hydrogen is the most abundant chemical substance in the universe, constituting roughly 75% of all baryonic mass.
4) Atomic mass: 1.00784 u
5) Atomic number: 1
        
             
        
        
        
We use samples to perform experiments. When sampling, we take test subjects from a larger group often known as "<em>population</em>" or at times "<em>universe</em>".
Sampling is a term we use to describe the process of selecting a small representitive group from a larger population. Sampling can often be divided in its simplest form into:
- <u>Random Samples</u>
- <u>Non-Random Samples.</u>
Which as their names imply, represent first a sample that is chosen by not specific method and whose probability is equal for the entire <em>population</em>, and secondly a sample chosen based on specific parameters. 
Sampling can then become more complex, being divided into more complex methods such as:
- <u>Systematic sampling
</u>
- <u>Stratified sampling
</u>
- <u>Cluster sampling</u>
etc. 
The one thing all of the sampling methods have in common is the fact that they will all draw their samples from one place. This place or aspect from which samples are drawn is known as the <em>population</em> <em>group </em>or sometimes coined as the <em>universe</em>, to represent the group in its entirety.
To learn more visit: 
brainly.com/question/350477?referrer=searchResults
 
        
             
        
        
        
"Water quality" may include the amounts of dissolved oxygen
and the levels of algal growth, pollutants which may be present and the pH level. Water quality effects also which types of organisms can
survive in a body of water.
 Shellfish require a high level
of dissolved oxygen and their abundance is an indication of good water quality. Shellfish are sensitive to changes in the ecosystem and they cannot easily escape changes in the water quality. These are one of the reasons why shellfish are good indicators of water quality.
        
             
        
        
        
Answer: Food spoilage
Explanation:
Lipid oxidation cause food spoilage because lipid oxidation is the oxidative degradation of lipids that occur when free hydroxyl attract electron from the fatty acids. These make the lipid radical to be unstable and the fatty acids reacts with oxygen to form fatty acid peroxyl radical which is the major causes of food deterioration. Oxidation occurs by defferent molecular mechanisms such as production of reactive oxygen precursors and free radicals. Continuous occurrence of this can result in lung damage.
 
        
             
        
        
        
Pseudopodia is the correct answer. 
Hope that helps!
-Grace