<h2>Answer:</h2>
It means the waves collides and constructive interference occurred.
<h3>Explanation:</h3>
If the two waves coming from the opposite direction collide with each other, there are two way of their interference.
- Constructive interference: An interference which results in the increase in energy. And it is when crust of a wave comes on the crust of second wave.
- Destructive interference: An interference which results in decrease in energy of the resulting wave and colliding waves cancel the result of each other.
Hence in experiment there will be constructive interference.
Fossil fuel emissions can create acid rain, which in turn increases the pH of ocean water, harming the organisms in the ocean.<span />
In this item, I supposed, that we are determine the molar fraction of oxygen and carbon dioxide in the sample. This can be done by dividing their respective partial pressures by the total pressure of the sample.
O2 : mole fraction = (100.7 mmHg) / (763.00 mmHg) = 0.13
CO2 : mole fraction = (33.57 mmHg) / (763.00 mmHg) = 0.044
Answers: O2 = 0.13
CO2 = 0.044
We determine the percent by mass of water in the compound by dividing the mass of water by the total mass. The total mass of Na2SO4.10H2O is equal to 322 g. The mass of water is 180 g.
percent by mass of water = (180 / 322)*(100 %) = 55.9%
Answer : The correct option is, (B) 
Solution :
According to the Graham's law, the rate of effusion of gas is inversely proportional to the square root of the molar mass of gas.

or,
..........(1)
where,
= rate of effusion of unknown gas = 
= rate of effusion of oxygen gas = 
= molar mass of unknown gas = ?
= molar mass of oxygen gas = 32 g/mole
Now put all the given values in the above formula 1, we get:


The unknown gas could be carbon dioxide
that has approximately 44 g/mole of molar mass.
Thus, the unknown gas could be carbon dioxide 