An element is a pure substance that cannot be separated or divided into simpler substances by any method (physical or chemical). The four common elements in all the living organisms are carbon, oxygen, hydrogen, nitrogen.
Thus, the four elements that make up about 96 % of body matter are carbon, oxygen, hydrogen, nitrogen (c).
Answer is: coefficient is one.
Chemical reaction: SiO₂ + 4HF → SiF₄ + 2H₂O.
Reaction is balanced when there are equal numbers of elements in both side of the chemical reaction.
HF - hydrofluoric acid, <span>highly corrosive, dissolves many materials.</span>
SiF₄ - silicon tetrafluoride.
The following observation would be included in a hypothesis: a connection between type of material and thermal energy transfer is developed (option C).
<h3>What is a hypothesis?</h3>
Hypothesis is a tentative conjecture explaining an observation, phenomenon or scientific problem that can be tested by further observation, investigation and/or experimentation.
The hypothesis is regarded as an educated guess because it predicts the possible outcome of an experiment.
The hypothesis is a statement that relates the independent variable of the experiment with the measured or dependent variable.
Therefore, the following observation would be included in a hypothesis: a connection between type of material and thermal energy transfer is developed.
Learn more about hypothesis at: brainly.com/question/13025783
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C. Rubbing the balloon against your hair
