Answer:
The reflection of sound waves
Explanation:
An echo is a reflection of sound that bounces of of one thing to another.
Smaller atoms and stronger bonds promotes greater hardness in minerals.
This is true otherwise cancer patients would have a hole in them and so would the hulk ;)
Answer: B (Items with densities lower than water will sink due to surface tension)
Explanation:
Surface tension is an intermolecular force exerted on the surface of water making it like a stretch elastic skin. Surface tension enables items with lesser densities than water, to float and slide on a water surface. Examples insects, leaves, paper etc
According to Archimedes principle an object denser than the fluid will sink. While objects less dense than the fluid will float.
Answer is (B) is false because items with densities higher then water will sink due to surface tension
