Nitrogen is the most abundant of the gases present in the atmosphere. 78 percent of the atmospheric air comprises of nitrogen, oxygen makes up for 21 percent and all other gases make up for the remaining one percent. Oxygen is a highly flammable gas and in the absence of nitrogen it would not have been possible to utilize this atmospheric oxygen, hence the presence of nitrogen reduces its flammability and also neutralizes the toxicity of other gases.
Answer:
3 s.
Explanation:
Echo is defined as the repetition of a sound produced by the reflection of sound waves from an obstructing surface like a wall, mountain etc.
v = f*lambda
Where,
Lambda = wavelength of the wave
f = frequency of the wave = 1/t
v = velocity of the wave.
Distance there and back = initial ditance * 2
= 525 x 2
= 1050.
Time taken, t = lamda/velocity
= 1050 / 350
= 3 s.
So the delay is 3 seconds.
Answer:
B. point on the surface directly above the earthquake
Explanation:
The earthquake involves the propagation of waves through the inner part of the earth due to natural or artificial processes. This majorly leads to the vibration of the earth crust of the affected region as the waves propagates. Thereby, causing sometimes the a violent break up of the surface of the earth from within.
Therefore, the focus of an earthquake is majorly called its epicenter, which is a point on the surface directly above the earthquake itself.
This is because the sound waves are way faster than the speed of light!
Wrong subject. Expect that to be in chemistry.
Here it is:
One mole of a compound/element contains the weight in grams equal to the sum of the molecular mass.
For MgCL2,
Mg=24.30
Cl=35.45
so the molecular mass = 24.30+2*35.45=24.30+70.9=95.20 (approximately).
=>
One mole of MgCl2 weighs 95.20 g.
305 g of MgCl2 = 305/95.20 = 3.20 moles, to 3 significant figures
Edit: improved accuracy of atomic masses.