Aurous is a cation of gold. Gold takes the name "aurum" (Au) with atomic number of 79. In its purest form, the element is bright, slightly yellow, soft, ductile, and malleable. The charge of aurous is +1. Sulfide, on the other hand, has a charge of -2.
Hence, the chemical formula of the compound is Au₂S and its systematic name is gold (I) sulfide.
Answer:
See explanation.
Explanation:
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In this case, according to the described chemical reaction, we first write the corresponding equation to obtain:

Thus, we proceed as follows:
Part 1 of 3: here, since the molar mass of silver and copper (II) nitrate are 107.87 and 187.55 g/mol respectively, and the mole ratio of the former to the latter is 2:1, we can set up the following stoichiometric expression:

Part 2 of 3: here, the molar mass of copper is 63.55 g/mol and the mole ratio of silver to copper is 2:1, the mass of the former that was used to start the reaction was:

Part 3 of 3: here, the molar mass of silver nitrate is 169.87 g/mol and their mole ratio 2:2, thus, the mass of initial silver nitrate is:

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1. For this question, the adjective small must be percepted in a relative sense. This is because it is not the smallest ion (that would be hydrogen). It could be that the antimony and beryllium ions are smaller compared to their neutral forms. This is because they donate electrons when ionized. As a result, the electrons are reduced, so does the electron cloud which makes the radius much smaller.
2. The periodic table is arranged in terms of increasing atomic number. For neutral atoms, the number of protons (atomic number) is equal to the number of electrons. So, the farther we go down the table, the higher the atomic number. The higher the atomic number, the bigger the electron cloud which makes the atomic radius bigger. Because by definition, atomic radius is the length from the nucleus to the farthest electron from the nucleus.