Answer:
B- He is correct. Evaporation is a physical change, but dissolving salt in water is a chemical change. The change in mass is evidence that a chemical change occurred.
Explanation: Dissolving Salt in water is a Chemical Change, Because the Salt arrangement is different in solid state than dissolved in water. As we can see in the image below, once the Salt is dissolved, it is separated into its ions, Na+ and Cl- Now, The evaporation process is a physical change, because the water doesn´t change its configuration H20 and it only changes its form, as we can see in the image below.
Answer:
microscopic light or Nano technology
Current always returns to the negative terminal.
<u>Explanation</u>:
Current flows from a positive to a negative terminal. It is due to the flow of negative electrons to positive side. The current flows from a high potential to a low potential. There is high concentration of electrons at the positive terminal and low concentration at the negative terminal. When the circuit is complete the electrons move from a high concentration to low concentration i.e; from positive terminal to negative terminal.
Answer:
Nodes.
Explanation:
Nodes are a point that are on a standing wave that never move.
