<span>If thermal energy (heat) must be added to a chemical reaction in order for the reaction to take place, the reaction is endothermic. </span>
Answer:
The concentration of hydrochloric acid would be estimated to be less.
Explanation:
This is because, the hydroxyl ions from water react with the hydrogen ions from the hydrochloric acid, hence decreasing the moles of hydrogen ions which lowers the acidic strength of Hydrochloric acid.
Answer:
<u>structural arrangements</u>
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<h2>properties of daimond: </h2><h3>appearance: transparent</h3><h3>hardness: very hard</h3><h3>thermal conductivity :very poor</h3><h3>electric conductivity: poor</h3><h3>density:</h3>

<h3>uses: jewellery and drilling</h3>
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<h2>properties of graphite:</h2>
<h3>appearance: black shiny</h3><h3>hardness: soft ,slippery to touch</h3><h3>thermal conductivity : moderate</h3><h3>electric conductivity: good</h3><h3>density:</h3>

<h3>uses:dry cell, electric arc, pencil lead, lubricant</h3>
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<h2>How Diamond and Graphite are chemically identical?</h2>
- On heating diamond or graphite in the air, they burn completely to form carbon dioxide.
- - Equal quantities of diamond and graphite when burned, produce exactly the same amount of carbon dioxide.
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<h2>Why the physical properties of diamond and graphite are so different?</h2>
Due to the difference in the arrangement of carbon atoms in diamond and graphite
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<em><u>hope</u></em><em><u> it</u></em><em><u> helps</u></em><em><u> you</u></em><em><u><</u></em><em><u>3</u></em></h2>
B) A chemical change because the nail reacts with water/oxygen to create rust (a type of oxide)
It has to be a metal, it can't be anything else.