Answer:
Hydrogen
Explanation:
It is considered a special element due to its flexibility in giving up & taking in electrons, therefore making it good for organic & inorganic chemistry. Hydrogen has only one proton and one electron and is the only element which has no neutrons. it is considered as the simplest element in the universe and gives a valid reason for it to be the most abundant and common element in the universe.
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Answer:
The number of electrons in the outermost shell of an atom determines its reactivity. Noble gases have low reactivity because they have full electron shells. Halogens are highly reactive because they readily gain an electron to fill their outermost shell.
Explanation:
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Answer: Option (c) is the correct answer.
Explanation:
Plants used to prepare food in the presence of sunlight. Therefore, plants uses solar energy to make food.
Due to solar energy various chemical reactions take place in the food.
Thus, we can conclude that chemical energy is stored in our food and this chemical energy start out as light energy from the sun.
Answer:
The half-cells separate the oxidation half-reaction from the reduction half-reaction and make it possible for current to flow through an external wire.
Explanation:
The given concentration of boric acid = 0.0500 M
Required volume of the solution = 2 L
Molarity is the moles of solute present per liter solution. So 0.0500 M boric acid has 0.0500 mol boric acid present in 1 L solution.
Calculating the moles of 0.0500 M boric acid present in 2 L solution:

Converting moles of boric acid to mass:

Therefore, 6.183 g boric acid when dissolved and made up to 2 L with distilled water gives 0.0500 M solution.