Answer:
719.83°C
Explanation:
The heat that the sample of Zinc gives is equal to the heat that water is absorbing. That is:
C(Zn) * m(Zn) * ΔT(Zn) = C(H2O) * m(H2O) * ΔT(H2O)
<em>Where:</em>
<em>C is specific heat (Zn: 0.390J/g°C; H2O: 4.184J/g°C)</em>
<em>m is mass (Zn: 2.50g; H2O: 65.0g)</em>
<em>ΔT (Zn: ?; H2O: (22.5°C - 20.0°C = 2.50°C)</em>
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Replacing:
0.390J/g°C * 2.50g * ΔT(Zn) = 4.184J/g°C * 65.0g * 2.50
ΔT(Zn) = 697.33°C
As final temperature of Zn is 22.50°C, initial temperature is:
Initial temperature: 697.33°C + 22.50°C
719.83°C
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Answer:
D) forms hydronium ions in water
Explanation:
Texture and conductivity are physical properties which makes answer A and B wrong. Answer C does not refer to a chemical reaction.
Answer: The correct option is 2.
Explanation: There are two types of nuclear reactions:
1) Nuclear fission: These reactions are defined as the reactions in which a heavier unstable nuclei breaks into two or more smaller stable nuclei.
2) Nuclear fusion: These reactions are the ones where two smaller nuclei fuse together or combine together to form a larger nuclei.
In the question, we need to find the fusion reaction which forms elements heavier than helium.
Option 1: In this fusion reaction occurs but the nuclei is Helium itself.
Option 2: In this also fusion reaction occurs and the nuclei is heavier than Helium which is Neon.

Option 3 and Option 4: These two reactions are nuclear fission reactions of Uranium-235 because one heavier element is breaking into more than 2 products.
Hence, the correct option is 2.