Answer:
0°C.
Explanation:
Hello,
In this case, given the heating curve of water on the attached document, we can notice that at 0 °C the solid starts melting, which means that the melting point is reached. Melting point is known as a physical change whereby a solid changes to liquid by the addition of heat as it allows the molecules to separate to each other.
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precipitation, it is called precipitation
Answer: bromine
Explanation:
There are a total of 2+2+6+2+6+2+10+5=35 electrons, meaning there are 35 protons. The element with atomic number 35 is <u>bromine</u>
The best answer is the first option. A bike rusting is an example of a chemical change since rusting is a chemical reaction. New substances are formed from this reaction. On the other hand, other choices given are just physical changes because only the shape or the physical form of the substances are being changed.
Answer:
a. 
b. 
c. 
Explanation:
Hello,
a. By applying the given information, one obtains:
b. By knowing that the propane has a molecular mass of 44g/mol, one obtains:
c. Here, the propane's combustion chemical reaction is stated:
This enthalpy of reaction is computed via:
Δ
Finally, since it is done for 20 lb of propane (), the obtainable energy is:
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