Answer:
They can't hear an echo in small room because in it the sound can't be reflected back. For an echo of a sound to be heard,the minimum distance between the source of sound and the walls of the room should be 17.2 m.
hopw it helps
Answer:
W = 0 J
Explanation:
The amount of work done by gas at constant pressure is given by the following formula:

where,
W = Work done by the gas
P = Pressure of the gas
ΔV = Change in the volume of the gas
Since the volume of the gas is constant. Therefore, there is no change in the volume of the gas:

<u>W = 0 J</u>
This is 2 hertz. You can mark out 2 full wavelengths in the second of time.
Answer: True
Explanation: When light is reflected off lets say a mirror it is bent and changes direction to bounce off of another wall or object. For example if you take a flash light and shine it into a mirror the light reflects into a different direction your welcome
The answer would be:
B. Chlorine, iodine and Fluorine
Barium has 2 valence electrons. To satisfy the BaX₂ , this would mean that Barium will need to give one of each of its electrons. The elements that need 1 electron would be those that have 7 valence electrons to complete the octet. These elements would fall in group 7 or halogens. Chlorine, iodine and fluorine are all in Group 7, so this would be the best choice.