A ream of copier paper weighs $2.25 \mathrm{~kg}$. How much does a sheet of copier paper weigh?

Find the sum of the first 80 positive even integers.

R$\'e$pondez $\`a$ la question. (Answer the question.)

What kinds of businesses support Lyon's economy?

A reaction that produced $4.8 \mathrm{mg}$ of taxol, an anticancer drug, is reported to have a yield of $38 \%$. What was the theoretical yield?

Dinitrogen pentoxide is a product of the reaction between $\mathrm{P}_4 \mathrm{O}_{10}$ and $\mathrm{HNO}_3$. Write a balanced equation for this reaction. Calculate the theoretical yield of $\mathrm{N}_2 \mathrm{O}_5$ if $79.4 \mathrm{~g}$ of $\mathrm{P}_4 \mathrm{O}_{10}$ is combined with an excess of $\mathrm{HNO}_3$. (Hint: One of the products is $\mathrm{HPO}_3$.)

Find the exact area.

Under the first arch of $f(x) = x \sin x.$

A small, monochromatic light source, radiating at $500 \ \mathrm{nm}$, is rated at $500 \ \mathrm{W}$. (a) If the source radiates uniformly in all directions, determine its radiant intensity. (b) If the surface area of the source is $5 \ \mathrm{cm^2}$, determine the radiant excitance. (c) What is the irradiance on a screen situated $2 \ \mathrm{m}$ from the source, with its surface normal to the radiant flux? d) If the receiving screen contains a hole with diameter $5 \ \mathrm{cm}$, ow much radiant flux gets through?

Calculate the extensions for these purchases:

50 reams of printer paper at $5.95 each, 36 pens at$2.20 each, and 24 printer cartridges at $32 each.

Magnesium oxide can be made by heating magnesium metal in the presence of oxygen. The balanced equation for the reaction is: $2 \mathrm{Mg}(s)+\mathrm{O}_{2}(g) \longrightarrow 2 \mathrm{MgO}(s)$ When 10.1 g of Mg reacts with 10.5 g $O_2$, 11.9 g MgO is collected. Determine the limiting reactant , theoretical yield, and percent yield for the reaction.

Are either the first or second reflections diffuse reflections? Explain.

What is the theoretical yield of chloroethane in the reaction of 19.4 g of ethene with 50 g of hydrogen chloride? What is the percent yield if 25.5 g of chloroethane is actually formed?

$$\mathrm{H}_2 \mathrm{C}=\mathrm{CH}_2+\mathrm{HCl} \longrightarrow \mathrm{CH}_3 \mathrm{CH}_2 \mathrm{Cl}$$

Contrast What is the difference between the definitions of open-ended questions and forced-choice questions?

Hoover Dam (is the highest arch-gravity type of dam in the United States. A plan view and cross section of the dam are shown in Fig. The walls of the canyon in which the dam is located are sloped, ream of the dam the vertical plane shown in Fig. is imately represents the cross section of the wate Use this vertical cross section to estime zontal force of the water on the dam. force acts.

A $10$-ream case of printer paper sells for $\$39.99$ and has a $47\%$ markup based on the selling price. Find the markup and cost of one case of paper.