Question

read the text. then, add the best concluding sentence. dissolving salt in water can demonstrate the role of electrical charges in atoms. a water molecule, made of two hydrogen atoms and one oxygen atom, has a negative charge on its oxygen side and a positive charge on its hydrogen side. in salt, the positively and negatively charged ions are weakly connected. waters negative charge pulls on the salts positive ion, while its positive charge pulls on the negative ion, separating them. the water molecules then surround the ions, evenly distributing in the mixture. this process explains how the movement of water molecules contributes to changes in temperature. this process demonstrates how electrical charges in water and salt can create a uniform solution. this process highlights the unique properties of water that make it essential for life on earth. this process emphasizes how the positive ions in salt distinguish it from other minerals.

Explanation:

The text focuses on the process of salt - water interaction due to electrical charges resulting in a solution. The best conclusion should summarize this process. The first option is about temperature changes which is not related. The third option about water's essentiality for life is too broad. The fourth option about salt's positive ions distinguishing it from other minerals is not the main point. The second option correctly sums up how electrical charges create a uniform solution.

Answer:

This process demonstrates how electrical charges in water and salt can create a uniform solution.