The temperature of a certain substance can be seen as the average speed of the atoms or molecules in that substance. In the liquid state of a substance the forces between the atoms or molecules are strong enough to keep them together, however with enough freedom to move, unlike in the solid state. If we would have a closer look at the surface of a liquid from sideways, we would see water molecules jumping out of the water and reentering it again. The lower the water temperature would be the lesser the amount of water molecules leaving the liquid phase would be. If water would be heated up and the temperature will reach 100 degrees C at normal atmospheric pressure, more water molecules would leave the water than reentering. Boiling has started. The temperature of the water remains at 100 degrees C, if the heating continues as the average speed of molecules will not increase, only the rate of molecules leaving the water will increase, until all the water in liquid state has been vapourized. The amount of heat needed to vapourize liquid water is called latent heat. Latent heat is a very important driving factor in the atmosphere and thus the weather.
Answer:
A general instrument, which is used to determine the concentration of hydrogen ion within the aqueous solution is known as a pH meter. The meter helps in determining the alkalinity or acidity, which is articulated in the form of pH. It is also called a potentiometric pH meter as it helps in finding the variation in electrical potential between a reference electrode and a pH electrode. This electrical potential variation is associated with the pH of the solution.
The potentiometric pH meter comprises a pair of electrodes and a basic electronic amplifier, some may even comprise a combination electrode and some sort of display that demonstrates pH units. The potentiometric pH meter generally exhibits a reference electrode or a combination electrode, and a glass electrode. The probes or electrodes are administered within a solution whose pH values are needed to be determined.
Answer:
2.74 x 1023 molecules of CO2.
Explanation:
There are 2.74 x 1023 molecules of CO2.
Answer is (4) - Se.
Among the given choices Se has the highest electronegativity value as 2.4 compared to others. Hence, Se shows <span>greatest attraction for electrons in a chemical bond.
</span>Electronegativity is
a value that tells us how an atom can attract electrons towards itself. <span>If
the electronegativity is high, then the attraction to the electrons is also high.
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