Answer:
Substances can change phase—often because of a temperature change. At low temperatures, most substances are solid; as the temperature increases, they become liquid; at higher temperatures still, they become gaseous.
The process of a solid becoming a liquid is called melting. (an older term that you may see sometimes is fusion). The opposite process, a liquid becoming a solid, is called solidification. For any pure substance, the temperature at which melting occurs—known as the melting point—is a characteristic of that substance. It requires energy for a solid to melt into a liquid. Every pure substance has a certain amount of energy it needs to change from a solid to a liquid. This amount is called the enthalpy of fusion (or heat of fusion) of the substance, represented as ΔHfus. Some ΔHfus values are listed in Table 10.2 “Enthalpies of Fusion for Various Substances”; it is assumed that these values are for the melting point of the substance. Note that the unit of ΔHfus is kilojoules per mole, so we need to know the quantity of material to know how much energy is involved. The ΔHfus is always tabulated as a positive number. However, it can be used for both the melting and the solidification processes as long as you keep in mind that melting is always endothermic (so ΔH will be positive), while solidification is always exothermic (so ΔH will be negative).
Table 10.2 Enthalpies of Fusion for Various Substances
Explanation:
Answer:
The pressure of the gas increases by a factor of 4
Answer:
The seed of the blackberry will be released in the faeces of the organisms. The seed of the blackberries will be distributed to different locations. When the seed will be dropped to a favourable location, the seed will germinate and a plant will grow from it. In this way, seeds are able to be dispersed at more favourable locations via animal sources. Hence, they will have better chances of growing in different areas.
In order to answer this question we must look at the image which I have attached.
The red atoms refer to oxygen atoms, the grey atoms are carbon atoms and the blue atoms are nitrogen. Therefore, the equation from the image suggests:
2CO + 2NO → 2CO₂ + N₂
Looking closely at the options given, several of them could be eliminated immediately since they are not balanced equations like B, C and E. Therefore, only A or D could be the answers.
The answer is option
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D.) 2CO + 2NO → 2CO2 + N2</span>