Answer:
Compound.
Explanation:
That would be compound as it consists of a number of elements bonded together. It is inorganic not organic.
Answer:
Q = -33.6kcal .
Explanation:
Hello there!
In this case, according to the equation for the calculation of the total heat of reaction when a fixed mass of a fuel like ethane is burnt, we can write:

Whereas n stands for the moles and the other term for the enthalpy of combustion. Thus, for the required total heat of reaction, we first compute the moles of ethane in 3 g as shown below:

Next, we understand that -337.0kcal is the heat released by the combustion of 1 mole of ethane, therefore, to compute Q, we proceed as follows:

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Answer:
In science, amodel is a representation of an idea, an object or even a process or a system that is used to describe and explain phenomena that cannot be experienced directly. Models are central to what scientists do, both in their research as well as when communicating their explanations.
Explanation:
In the past a scientist named dalton produced an atomic theory. There were certain problems regarding his views. So, later on scientists like chadwick, rutherford and thompson added some fresh light for the real identification of the atom.
dalton said the atom was the smallest unit and it CANNOT BE DIVIDED ANY FURTHER.
NOTE... this was renected with the discovery of the proton, neutron and electron as the sub atomic particles.
Answer:
D, Li2S
Explanation:
This is because Lithium, which is in group IA of the periodic table, has a charge of +1. Sulfur will have a charge of -2 because it is in group 6A in the periodic table, which means to balance these out, there needs to be 2 lithium ions which would result in a charge of +2. With Lithium now having a charge of +2 due to having two atoms in the compound, and sulfur already having a charge of -2 as one atom, these two cancel out meaning the compound is neutral.