Answer:
Sound waves required a medium.
Explanation:
In space, there is only vacuum hence no any medium for sound wave travel.
Since sound waves are mechanical waves, they require a material medium such as air, hence no sound transmission.
Answer:
O(Oxygen)
Explanation:
2+2+4=8
And the eighth element of the periodic table is Oxygen
Answer:
Your statement is right.
Explanation:
When fuels are burned in vehicle engines, high temperatures are produced. At this high temperature, nitrogen and oxygen from the air combine with each other to produce nitrogen monoxide (NO). When this nitrogen monoxide is released in the air from vehicle exhaust systems, it combines with oxygen present in the air to form nitrogen dioxide (NO2).
The main difference between concentration and density is that concentration refers to how much of a substance is present in a mixture, whereas density refers to the mass of a substance per unit volume.
