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Questions in chemistry

📝 Answered - Complete the Nuclear Decay Table: | Decay Type | Mass of particle | Charge of particle | Symbol | |---|---|---|---| | Alpha | 4 | +2 | [tex]$\frac{4}{2} He$[/tex] | | Beta | 0 | -1 | [tex]$-i e$[/tex] | | [?] | 0 | | [tex]$i o \gamma$[/tex] | | Positron Emission | | +1 | | What goes in the missing cells? Choose from the following: Alpha Positron Gamma

📝 Answered - The equation for the pH of a substance is [tex]$pH =-\log \left[ H ^{+}\right]$[/tex], where [tex]$H +$[/tex] is the concentration of hydrogen ions. A basic solution has a pH of 11.2. An acidic solution has a pH of 2.4. What is the approximate difference in the concentration of hydrogen ions between the two solutions? A. [tex]$1.6 \times 10^{-9}$[/tex] B. [tex]$4.0 \times 10^{-3}$[/tex] C. [tex]$6.7 \times 10^{-1}$[/tex] D. [tex]$1.6 \times 10^{11}$[/tex]

📝 Answered - Who is credited with creating the first periodic table? A. Johann Dobereiner B. Henry Moseley C. Dmitri Mendeleev D. John Newlands

📝 Answered - Which will increase the rate of a chemical reaction? A. adding a catalyst B. decreasing the pressure C. decreasing the temperature D. removing a catalyst

📝 Answered - Which element is placed in the same period as ruthenium but has a higher atomic number than it? A. bismuth B. osmium C. silver D. zirconium

📝 Answered - Which substance is a compound? A. water B. gold C. oxygen D. hydrogen

📝 Answered - The solubility of calcium carbonate is [tex]$14 \frac{\text { milliene }}{\text { film }}$[/tex]. This rate means that 14 milligrams of calcium carbonate can dissolve in 1 liter of water. How much water would be required to fully dissolve 11 grams of calcium carbonate? Express your answer to the correct number of significant figures. One milligram is equal to 0.001 grams. I would take [$\square$] liters of water to fully dissolve [tex]$11$[/tex] grams of calcium carbonate

📝 Answered - How many grams of $Mg(OH)_2$ are in $7.5 \times 10^{23}$ formula units (f.un.) of $Mg(OH)_2$? Which part of the conversion factor goes in the green box? $6.02 \times 10^{23}$ f.un. 58.32 g 1 mole

📝 Answered - Write the electronic configurations of sulfur and write its position in the modern periodic table.

📝 Answered - A scientist is working with methane $(CH_4)$ and butane $(C_4H_{10})$. Which statement best compares these chemicals? A. They are two different types of molecules that each contain the same number of atoms. B. They are two different types of atoms that are each made up of a different number of elements. C. They are compounds made of the same two elements, but each contain different numbers of atoms. D. They are matter made of the same two compounds, but each contain different types of elements.