The earths gravity attracts the molecules and collects the most near the surface. They all have weight and therefore have more pressure at the surface, as well. As you go higher, the attraction becomes less and these molecules some times fly off into space. This layer of equilibrium has the least of weight or pressure.
The various pressures are measured by precision instruments called barometers or pressure sensors and expressed in inches of mercury or millibars. <span>Air has a weight too, although not very much, If you "pile" the air mile high, the bottom pressure is heavier because of all the air sitting on top of it, therefore the pressure decreases with altitude, because there is less air "piled up" </span>
<span>An analogy would be the same with water.</span>
Planes have these instruments that tells the crew the altitude above sea level they are at when flying.
Answer:
This is an example of a food chain
Explanation:
Think of it as a chain reaction. The grass feeds and nourishes the prairie dog. Upon eating the prairie dog, the coyote gets the nutrients from both the grass the prairie dog ate and from the prairie dog itself.
Answer:
Mass = 2.89 g
Explanation:
Given data:
Mass of NH₄Cl = 8.939 g
Mass of Ca(OH)₂ = 7.48 g
Mass of ammonia produced = ?
Solution:
2NH₄Cl + Ca(OH)₂ → CaCl₂ + 2NH₃ + 2H₂O
Number of moles of NH₄Cl:
Number of moles = mass/molar mass
Number of moles = 8.939 g / 53.5 g/mol
Number of moles = 0.17 mol
Number of moles of Ca(OH)₂ :
Number of moles = mass/molar mass
Number of moles = 7.48 g / 74.1 g/mol
Number of moles = 0.10 mol
Now we will compare the moles of ammonia with both reactant.
NH₄Cl : NH₃
2 : 2
0.17 : 0.17
Ca(OH)₂ : NH₃
1 : 2
0.10 : 2/1×0.10 = 0.2 mol
Less number of moles of ammonia are produced by ammonium chloride it will act as limiting reactant.
Mass of ammonia:
Mass = number of moles × molar mass
Mass = 0.17 mol × 17 g/mol
Mass = 2.89 g
Answer: After 4710 seconds, 1/8 of the compound will be left
Explanation:
Using the formulae
Nt/No = (1/2)^t/t1/2
Where
N= amount of the compound present at time t
No= amount of compound present at time t=0
t= time taken for N molecules of the compound to remain = 4710 seconds
t1/2 = half-life of compound = 1570 seconds
Plugging in the values, we have
Nt/No = (1/2)^(4710s/1570s)
Nt/No = (1/2)^3
Nt/No= 1/8
Therefore after 4710 seconds, 1/8 molecules of the compound will be left
