Answer:
Lead is a chemical element with the symbol Pb (from the Latin plumbum) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point.
Explanation:
<span> The atomic number increases by one and the element becomes a different element. </span>
Answer:
The breaking of the chemical bonds of a storage molecule transfer energy, no what molecule is stored.
Explanation:
Being successful of plants and animals does not necessary depend on the stored molecule but on the energy being transferred during their breaking.
<u>Answer:</u> The formation of given amount of oxygen gas results in the absorption of 713 kJ of heat.
<u>Explanation:</u>
To calculate the number of moles, we use the equation:

Given mass of oxygen gas = 83 g
Molar mass of oxygen gas = 32 g/mol
Putting values in above equation, we get:

For the given chemical equation:

<u>Sign convention of heat:</u>
When heat is absorbed, the sign of heat is taken to be positive and when heat is released, the sign of heat is taken to be negative.
By Stoichiometry of the reaction:
When 3 moles of oxygen gas is formed, the amount of heat absorbed is 824.2 kJ
So, when 2.594 moles of oxygen gas is formed, the amount of heat absorbed will be = 
Hence, the formation of given amount of oxygen gas results in the absorption of 713 kJ of heat.
The properties of substances can be used to put the into groups.
<h3>Grouping of substances</h3>
In chemistry, it is often necessary to put substances into groups based on similarity in their properties. This is what led to the idea of a periodic table of elements.
Similarly, when we have unknown substances, we can group them according to the similarities in their properties.
Learn more about properties of substances: brainly.com/question/19886211