Answer:
A. Bubbles formed
Explanation:
When a student added a piece of limestone to a solution of hydrochloric acid, bubbles are formed.
The bubbles are as a result of the CO2 gas that is formed.
Below is the reaction:
CaCO3+2HCl → CO2+H2O + Ca++ + 2Cl-
From the left hand side, we can see that the reaction is with limestone and hydrochloric acid. Their reaction forms carbon dioxide gas (CO2), water (H2O), dissolved calcium (Ca++) and dissolved chlorine (Cl-) on the right hand side.
With due observation, bubbles will be seen evolving from the reaction. These bubbles formed is the carbon dioxide gas which reveals that a reaction is taking place.
The use of General Zaroff as a supporting character for Rainsford help the author develop the story's themes as it shows the distinction between humans and animals and the unreliability of sensation.
<h3>What is a theme?</h3>
It should be noted that a theme simply means the underlying message that can be deduced in a literary work.
In this case, the use of General Zaroff as a supporting character for Rainsford help the author develop the story's themes as it shows the distinction between humans and animals and the unreliability of sensation.
Learn more about theme on:
brainly.com/question/11600913
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False, a teacher always gives clue of the main idea
