<u>Answer:</u> This illustrates law of conservation of mass.
<u>Explanation:</u>
Dalton's theory is based on mainly two laws which are law of conservation of mass and law of constant proportion.
Law of conservation of mass states that mass can neither be created nor be destroyed but it can only be transformed from one form to another form.
This also means that total mass on the reactant side must be equal to the total mass on the product side.
The chemical equation for the decomposition of calcium carbonate follows:

We are given:
Mass of calcium carbonate = 100 grams
Mass of calcium oxide = 56 grams
Mass of carbon dioxide = 44 grams
Total mass on reactant side = 100 g
Total mass on product side = 56 + 44 = 100 g
As, the total mass on reactant side is equal to the total mass on product side.
Thus, this illustrates law of conservation of mass.
<span>Answer: a mixture.
</span><span>Justification:</span>
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</span><span>1) Pure substances have a definite chemical formula: the same kind of atoms with the same fixed ratios and chemical bonds. Therefore, the percents of each element do not varye.
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2) Elements and compounds are pure substaces. For example, Fe, Mg, Ti, are elements, and CO₂, CO, H₂CO₃ are compounds. Each of them will have always the same kind of atoms, in the same ratio and with the same chemcial bonds. Therefore the percents of the elements do not varye.
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<span>3) Mixtures are formed by the physical combination (not chemical bonds) of different elements or compounds in variable proportions. As indicated, this describes the material bronze, in virtue of the variation of its composition. Other examples of mixtures are solutions (like brines), air, ocean water, and milk: different brines, different oceans and different milk have different contents of elements or compounds.
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<span>A piece of sodium metal can be described as a soft silvery white metal that is highly reactive and can sometimes cause explosions. This is the reason why it doesn't occur naturally as an isolated metal. Instead, different sodium containing compounds undergo different processes to isolate the sodium metal.</span>
Answer:
KBr > NaCl >
>
Explanation:
Generally, the higher the lattice energy of the substance, the lower the solubility of the substance. The lattice energy of KBr is the lowest, follow by that NaCl and that of
while that of
is the highest. Based on the relationship between the lattice energy and solubility, the solubility of the substances ranging from the highest to lowest is KBr > NaCl >
>
.