I spent 31 years teaching Chemistry and Physics ranging from the middle school level to college level and AP level. Before beginning my teaching career, I worked as an analytical chemist in quality control.
Molten iron cooling to solid iron is an example of(a) sublimation(b) condensation(c) freezing(d) melting
True or false? After being heated to above its boiling point, ethanol is no longer ethanol but something else. Explain.
You are presented with a block made of some pure metal and told the metal is gold, but you have your doubts. Using a thermometer, how can you determine whether the metal is gold?
Water $\left(\mathrm{H}_{2} \mathrm{O}\right)$ and carbon dioxide $\left(\mathrm{CO}_{2}\right)$ are produced in a chemical reaction when methane $\left(\mathrm{CH}_{4}\right)$ and oxygen $\left(\mathrm{O}_{2}\right)$ are combined and heated. Which are the reactants, and which are the products?
What, if anything, is wrong with the following chemical reaction?$\mathrm{Cl}_{2}(g)+\mathrm{Br}_{2}(I) \rightarrow 2 \mathrm{HCl}(g)+2 \mathrm{HBr}(g)$(a) It is not a chemical reaction. It is only a physical transformation.(b) The products include elements that are not in the reactants.(c) There is nothing wrong with the chemical reaction.
Radioactive Decay SeriesNeptunium-237 decays in a series of 12 steps, in the followingprogression: alpha, beta, alpha, alpha, beta, alpha, alpha, alpha,beta, alpha, beta, and alpha, ending with Thallium-205. Below,write 9 different series of nuclear reactions that shows this decayseries.
Usually carbon forms four bonds, nitrogen three, oxygen two, andhydrogen only one.Using this information draw the following:A compound that contains one carbon atom, one nitrogen atom,and as many hydrogen atoms as needed.A compound that contains one carbon atom, one oxygen atom, andas many hydrogen atoms as needed.
Calculate the formula mass for each compound.Express your answer in atomic mass units to two decimalplaces.A) H2SO3B) SrBr2C) CBr4D) Zn(NO3)2
Perform the following calculations on a sheet of paper. Make sure you show your work with correct conversion factors, units, and significant figures. Upload your calculations as a PDF file here.
a. A pen has a length of 7.6 cm. What is its length in meters? Express the answer using scientific notation.b. A patient weighs 155 lbs. What is the patient's weight in grams? Express the answer using scientific notation.c. A doctor needs 225 mg of morphine. It is only available in a 0.40 g/mL solution. How many mL of solution are required to deliver this 225 mg?
The diameter of a neon atom is about 1.5x10^2 pm. If we could line up neon atoms side by side in contact with one another, how many atoms would it take to span a distance of 1 cm? Show conversion work and any other work done to arrive at the answer!
HI(aq) + KHSO3(aq) ā H2O(l) + KI(aq) + SO2(g)(NH4)2SO4(aq) + Ca(OH)2(aq) ā 2NH3(g) + CaSO4(s) + 2H2O(l)HCl(aq) + KHCO3(aq) ā H2O(l) + KCl(aq) + CO2(g)HNO3(aq) + Na2SO3(aq) ā H2O(l) + NaNO3(aq) + SO2(g)
