Answer:
<h3>A . Alkali metals</h3>
Explanation:
The highlighted elements of the periodic table belong to the alkali metal element family. The alkali metals are recognized as a group and family of elements. These elements are metals. Sodium and potassium are examples of elements in this family.
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Answer:
Cost to supply enough vanillin is 
Explanation:
Threshold limit of vanillin in air is
per litre means there should be
of vanillin in 1L of air to detect aroma of vanillin.

So, 
So amount of vanillin should be present to detect = 
As cost of 50 g vanillin is
therefore cost of
vanillin = 
Explanation:
It is given that vapor pressure of pure water at 296 K is 2778.5 Pa.These vapors will result in the formation of an ideal gas.
Now, as water is covered with oil and contains only 1% molecules of water. Hence, the vapor pressure of this mixture will also be equal to the vapor pressure of pure water.
So, vapor pressure of mixture = 1% vapor pressure of pure water
Therefore,
=
= 27.785 Pa
Thus, we can conclude that the equilibrium vapor pressure of water above the oil layer is 27.785 Pa.
£ is not a molecule. It is a currency. That is pounds sterling, used in the U.K.
1. Curiosity-They love to learn 2. Open-mindedness- he accepts criticisms fairly well
3. Rationality- he does not believe in superstitions and think that everything has a scientific explanation
4. Critical Mindedness & Correct Judgement- he does not easily jump to conclusions but tries to verify his results by (if possible) repeating the experiment
5. Intellectual Honesty- does not alter his observations and writes the correct observations he has seen
6. Objectivity-<span> he writes accurate results
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