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Questions in chemistry

[Done] What is the gram-formula mass of [tex]$\text{Fe(NO}_3)_3$[/tex]? 1. 146 g/mol 2. 194 g/mol 3. 214 g/mol 4. 242 g/mol

[Done] One beneficial use of radioisotopes is: 1. Detection of disease 2. Neutralization of an acid spill 3. Decreasing the dissolved \(O_2(g)\) level in seawater 4. Increasing the concentration of \(CO_2(g)\) in the atmosphere

[Done] Compared to the charge of a proton, the charge of an electron has: (1) a greater magnitude and the same sign (2) a greater magnitude and the opposite sign (3) the same magnitude and the same sign (4) the same magnitude and the opposite sign

[Done] Two forms of solid carbon, diamond and graphite, differ in their physical properties due to the differences in their 1. atomic numbers 2. crystal structures 3. isotopic abundances 4. percent compositions

[Done] Which change results in the formation of different substances? 1. Burning of propane 2. Melting of NaCl (s) 3. Deposition of CO2(g) 4. Solidification of water

[Done] Which atom has the largest atomic radius? A. potassium B. rubidium C. francium D. cesium

[Done] The coefficients in a balanced chemical equation represent: 1. the mass ratios of the substances in the reaction 2. the mole ratios of the substances in the reaction 3. the total number of electrons in the reaction 4. the total number of elements in the reaction

[Done] Compared to the physical and chemical properties of the compound NO2, the compound N2O has 1. different physical properties and different chemical properties 2. different physical properties and the same chemical properties 3. the same physical properties and different chemical properties 4. the same physical properties and the same chemical properties

[Done] Given the balanced equation representing a reaction: \[ \text{O}_2 \rightarrow \text{O} + \text{O} \] What occurs during this reaction? 1. Energy is absorbed as bonds are broken. 2. Energy is absorbed as bonds are formed. 3. Energy is released as bonds are broken. 4. Energy is released as bonds are formed.

[Done] A sample of a substance has these characteristics: - Melting point of 981 K - Hard, brittle solid at room temperature - Poor conductor of heat and electricity as a solid - Good conductor of electricity as a liquid or in an aqueous solution This sample is classified as: 1. a metallic element 2. a radioactive element 3. a molecular compound 4. an ionic compound