At room temperature oxygen,
is present in the gas phase.
A gas is defined as a substance which is characterized by the rapidly movement of molecules which are widely separated. The shape and volume of gas is not definite that is they take on the shape of the container in which it is placed. The gas molecules have minimum inter-nuclear attractions and thus have high kinetic energy.
Thus, the sentences that describes oxygen at room temperature are:
- It has no definite volume and takes the shape of its container.
- Its particles move fast enough to overcome the attraction between them.
- It has more energy than it would be at a cooler temperature as the kinetic energy is directly proportional to the temperature that is kinetic energy increases on increasing the temperature.
Answer: option E. nitrogen is much more electronegative than hydrogen.
Explanation:
Answer:
Acid rain
Explanation:
The independent variable in the hypothesis statement is the acid rain. An independent variable is usually the cause in an experiment.
This variable give rises to the effects observed as the dependent variable.
In the presence of the acid rain, the fish population will increase.
The dependent variable is the fish population or number of fishes.
The independent variable is the acid rain as it is the cause of the effect observed on the fish population.
Enzymes that eventually break down the surface of bacteria are found in saliva, mucus, and tears, which act as chemical barriers against infection.
Enzymes found in saliva, mucous, as well as tears that degrade bacterial surfaces serve as chemical barriers preventing infection. The stomach's acid as well as the acid in sweat both destroy cellular pathogens, and even the semen contains antibacterial proteins.
There is no chemical and physical barrier offered by macrophages. Instead of acting as a barrier, macrophages target pathogens once they have already entered the body. Physical barriers include mucus as well as stratified squamous epithelium, whereas chemical barriers include saliva and urine.
Therefore, Enzymes that eventually break down the surface of bacteria are found in saliva, mucus, and tears, which act as chemical barriers against infection.
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