Answer:
3) The calculated density would be high, because the volume would be incorrectly measured low.
Explanation:
Density is defined as mass per unit volume. It means the density is inversely proportional to the volume.
A solid with a hollow center will have high volume due to air inside the hollow area that will lead to low density.
But the error in the calculation of density is that the "density would be high, because the volume would be incorrectly measured low."
Hence, the correct answer is "3)"
1) Answer: A hot pack feels warm when chemicals in it combine.
Explanation: Reactions or process in which heat is released(produced) are known as exothermic reactions or process and those in which the heat is absorbed are known as endothermic reactions or process.
If a beaker feels cools when chemical in it react then it means the chemicals have absorbed the heat energy from its surroundings and so it is an example of an endothermic process.
A hot pack feels warm when chemicals in it combine means the energy is released in the chemical reaction and so it is an example of an exothermic process.
Plants use the sun's energy for photosynthesis which is a process of forming food for the plants. Energy acts as a reactant in this process and so it is an example of endothermic process.
Frying an egg by heating it on a stove is an example of an endothermic process as the heat is required to fry the egg.
So, the only exothermic process is the second one, "A hot pack feels warm when chemicals in it combine."
2) In the given equation, heat is written as a product means the heat is released in the equation and so it is an example of an exothermic reaction.
So, the correct choice is the last one " It is exothermic because energy is released."
Answer:
Lithium's mass number would decrease by 1
Explanation:
Answer:
Explanation:
First, we find in the tables the ΔH of formation of each compound. As you can see in the (image 1)
Then we solve the ecuation for ΔH°reaction
ΔH°reaction=∑ΔH°f(products)−∑ΔH°f(Reactants)
ΔH°reaction= (-2* 393.5 - 2*285.8) - (52.4 + 0) kJ/mol
ΔH°reaction = -1.41 *10^3 kJ/mol
Answer:
D. is the Answer. ✅
Explanation:
The Moon is 1/4 the size of Earth.
A is not right because Moon isn't a dwarf planet.❌
B is not right because the Moon isn't 1/2 the size of Earth.❌
C is not right because the Moon is no where near as large as Earth.❌
