Answer:
Carbon dioxide (CO₂) is an important green house gas. A small increase in the concentration of this gas can lead to the global rise in the surface temperature. Over the last 100 years, this gas has increased significantly. One of the main cause behind this the anthropogenic activities.
After the setup of the industrial revolution, there has been a large increase in this CO₂ concentration, as there are numerous large factories and indutries that releases this harmful gases. In addition to this, the burning up of fossil fuel also is responsible for the emission of large amount of carbon into the atmosphere.
Deforestation also is another cause, because trees are no longer there in vast quantities which takes up a large number of atmospheric carbon and in return liberates plenty of oxygen.
Thus, the activities done by man over the last century has led to the increase in the concentration of CO₂ into the atmosphere.
Answer: Natural selection.
Explanation:
The natural selection is the process by which the organism that best suits the characters will survive and the organism which cannot adapt the changes will die.
The predators feed on their prey and the organism which hides easily in the environment due to its color is safe and the animals that cannot camouflage will die.
This is natural selection that more favored character is carried out over generations and other that cannot survive die.
Explanation:
Let us assume that the given data is as follows.
V = 3.10 L, T =
= (19 + 273)K = 292 K
P = 40 torr (1 atm = 760 torr)
So, P = 
= 0.053 atm
n = ?
According to the ideal gas equation, PV = nRT.
Putting the given values into the above equation to calculate the value of n as follows.
PV = nRT

0.1643 = 
n = 
It is known that molar mass of ethanol is 46 g/mol. Hence, calculate its mass as follows.
No. of moles =
mass =
g
= 0.315 g
Thus, we can conclude that the mass of liquid ethanol is 0.315 g.
Given: C3H8(g) + O2(g) ----> CO2 (g) + H2O (g)
Step : Put a 3 in front of CO2 (g) to balance C
=> C3H8(g) + O2(g) ----> 3CO2 + H2O to balance H
Step 2: Put a 4 in front of H2O
=> C3H8 (g) + O2(g) -----> 3CO2 (g) + 4H2O (g)
Step 3: Given that there are 3*2 + 4 = 10 O to the right side, put a 5 in front of O2 to balance O:
=> C3H8(g) + 5O2(g) -----> 3CO2(g) + 4H2O(g)
You can verify that the equation is balanced.
So, the answer is that the coefficient in front of O2 is 5.
Answer:
The frequency is 
Explanation:
From the question we are told that
The energy required to ionize boron is 
Generally the ionization energy of boron pre atom is mathematically represented as

Here
is the Avogadro's constant with value 
So

=> 
Generally the energy required to liberate one electron from an atom is equivalent to the ionization energy per atom and this mathematically represented as

=> 
Here h is the Planks constant with value 
So

=> 