Answer: Option (b) is the correct answer.
Explanation:
A chemical reaction in which heat energy is absorbed by the reactant molecules is known as an endothermic reaction.
Therefore, upon completion of this reaction the container in which reaction is carried out becomes colder.
A chemical reaction in which heat energy is released by the reactant molecules is known as an exothermic reaction.
Therefore, upon completion or during this type of reaction the container in which reaction is carried out becomes hot.
Thus, we can conclude that when the test tube gets colder as the reaction takes place then it means this chemical reaction is endothermic reaction.
Answer:
A is a physical change, no atoms are being lost its still in it original form
B is a chemical change, it is losing atoms and changing into a new substance
Explanation:
In 1897 the theory of understanding the energetics and arrangement of atoms was developed by Josheph Larmor.
It is also called solar system model of atom.
<h3>What is solar system model of atom? </h3>
The “solar system” model indicates an atom as a whole massive positive body that is the nucleus similar to the sun in the solar system with negative entities that are the electrons as the planets in our solar system revolving around it.
<h3>Why this model not accepted? </h3>
The thought about this model is that the electrons which revolves around the nucleus are the charged particles which have centripetal acceleration during the revolution. Even if they all are travelling at the same velocity in modulus, the trajectory of their velocity varies with respect to time which resulting in the centripetal acceleration. An accelerated charge particle will emit energy in the form of electromagnetic radiation. This results in the loss of energy which causes the charged particle to fall inside the nucleus. Therefore, this fails to happen.
Thus, we concluded that In 1897 the theory of understanding the energetics and arrangement of atoms was developed.
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Answer:
Noble gases already have a full outer shell, so they do no take part in chemical reactions.
