Answer:
C
Explanation:
Electromagnetic waves travel at the speed of light and do not require molecules (gas, solid or liquid) to vibrate and travel.
Soundwaves when singing or from thunder vibrate particles to reach our ears and are known as mechanical waves.
Explanation:
The pH of a weak base falls somewhere between 7 and 10.
6.52 × 10⁴ L. (3 sig. fig.)
<h3>Explanation</h3>
Helium is a noble gas. The interaction between two helium molecules is rather weak, which makes the gas rather "ideal."
Consider the ideal gas law:
,
where
is the pressure of the gas,
is the volume of the gas, 
is the number of gas particles in the gas, 
is the ideal gas constant, and
is the absolute temperature of the gas in degrees Kelvins.
The question is asking for the final volume of the gas. Rearrange the ideal gas equation for volume:
.
Both the temperature of the gas, , and the pressure on the gas changed in this process. To find the new volume of the gas, change one variable at a time.
Start with the absolute temperature of the gas:
,
.
The volume of the gas is proportional to its temperature if both and stay constant.
- won't change unless the balloon leaks, and
- consider to be constant, for calculations that include .
.
Now, keep the temperature at 
and change the pressure on the gas:
,
.
The volume of the gas is proportional to the reciprocal of its absolute temperature 
if both and stays constant. In other words,
(3 sig. fig. as in the question.).
See if you get the same result if you hold constant, change , and then move on to change .
Answer:
it is a replacement reaction
