Answer 1 and 2 are true for alkaline solutions.
Acids have a pH below 7. (this is the answer)
Both acids and bases are electrolytes as they have free moving ions.
Feel free to comment if you want further explanation.
The correct answer is C) A substance changes color when heated, but changes back when cooled. Hope this helps.
Sound waves need to travel through a medium such as solids, liquids and gases. The sound waves move through each of these mediums by vibrating the molecules in the matter. ... This enables sound to travel much faster through a solid than a gas. Sound travels about four times faster and farther in water than it does in air.
Sounds can travel at approximately 6000 metres per second in some solids and at a quarter of this speed in water. This is because the molecules of solids are more tightly packed together than in liquids and those in liquids are more tightly packed than in gases.
