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Questions in chemistry

[Answered] Write the electronic position in the modern periodic table. On what basis are the group and period separated in the modern periodic table? In which group do Fluorine, Chlorine, and Bromine lie in the periodic table? Which one is more reactive among them? If you are given a chance to make improvements in the modern periodic table, what changes would you make in it? Explain with reasons.

[Answered] A sample of an unknown substance has a mass of 0.465 kg. If [tex]$3,000.0 J$[/tex] of heat is required to heat the substance from [tex]$50.0^{\circ} C$[/tex] to [tex]$100.0^{\circ} C$[/tex], what is the specific heat of the substance? Use [tex]$q=m C_p \triangle T$[/tex].

[Answered] Which of the following electrolytes would you use to electroplate silver (Ag) on iron (Fe)? A. [tex]$FeSO _4$[/tex] B. [tex]$CuCl _2$[/tex] C. [tex]$AgNO _3$[/tex] D. [tex]$Zn \left( ClO _3\right)_2$[/tex]

[Answered] A sample of propane [tex]$\left( C _3 H _8\right)$[/tex] has a mass of 0.47 g. The sample is burned in a bomb calorimeter that has a mass of 1.350 kg and a specific heat of [tex]$5.82 J /\left( g \cdot{ }^{\circ} C \right)$[/tex]. How much energy is released by the reaction if the temperature of the calorimeter rises by [tex]$2.87^{\circ} C$[/tex]? Use [tex]$q=m C_p \Delta T$[/tex].

[Answered] The dosage of quinine when a $145-lb$ adult takes a $200.-mg$ tablet is weight. How many $\mu g$ of drug per kg of body? A. 15.2 B. $1.60 \times 10^3$ C. $4.41 \times 10^5$ D. $1.38 \times 10^6$ E. $3.04 \times 10^3$

[Answered] Each atom of an element has the following electron configuration: [tex]$1 s^2 2 s^2 2 p^6 3 s^2 3 p^6 4 s^2 3 d^{10} 4 p^6 5 s^2 4 d^{10} 5 p^5$[/tex] What is the name of the element? A. bromine B. iodine C. tellurium D. xenon

[Answered] Two reactants combine to form one new product. Which of the following best describes this type of chemical reaction? A. Combustion B. Synthesis C. Decomposition D. Single Replacement

[Answered] Andy has two samples of liquids. Sample A has a pH of 4, and sample B has a pH of 6. What can Andy conclude about these two samples?

[Answered] The symbol for a radioactive nuclide is ${ }_{84}^{210} Po$. Which statement is correct? A. The atomic number of the radioactive nuclide is 210. B. The mass number of the radioactive nuclide is 294. C. The number of neutrons present in the nucleus of each atom is 126. D. The number of protons present in the nucleus of each atom is 210.

[Answered] Which best describes a compound such as sodium chloride? A. a pure substance that can be separated into different elements by physical means B. a mixture of two common substances that can be separated by chemical means C. a mixture of two common elements that can be separated by physical means D. a pure substance that can be separated into different elements by chemical means