Sterling silver is a solid solution of silver and copper. If a piece of a sterling silver necklace has a mass of 105.0 g and a volume of 10.12 mL, calculate the mass percent of copper in

The dosage for an antibiotic is prescribed at 8.0 mg per kilogram of body weight, taken twice daily for two weeks. What total mass of antibiotic will be taken by a 180-lb person for the two-week period?

Express 743 000 000 in scientific notation to the following number of significant figures: a. one significant figure, b. two significant figures, c. four significant figures.

Round each number to four significant figures, and write the answer in scientific notation. 308,659,000 mm

Which of the following describes a chemical property?

The density of iron is $\ce{7.87 g/cm^3}$.

A platinum wire glows red when heated.

An iron bar rusts.

Aluminum is a silver-colored metal.

A parsec is an astronomical unit of distance where 1 parsec = 3.26 light years (1 light year equals the distance traveled by light in one year). If the speed of light is 186,000 mi/s, calculate the distance in meters of an object that travels 9.6 parsecs.

A person weighed 15 pennies on a balance and recorded the following masses:

$$\begin{array}{lll} 3.112\ \mathrm{g} & 3.109\ \mathrm{g} & 3.059\ \mathrm{g} \\ 2.467\ \mathrm{g} & 3.079\ \mathrm{g} & 2.518\ \mathrm{g} \\ 3.129\ \mathrm{g} & 2.545\ \mathrm{g} & 3.050\ \mathrm{g} \\ 3.053\ \mathrm{g} & 3.054\ \mathrm{g} & 3.072\ \mathrm{g} \\ 3.081\ \mathrm{g} & 3.131\ \mathrm{g} & 3.064\ \mathrm{g} \end{array}$$

Curious about the results, he looked at the dates on each penny. Two of the light pennies were minted in 1983 and one in 1982. The dates on the 12 heavier pennies ranged from 1970 to 1982. Two of the 12 heavier pennies were minted in 1982. The person calculated the average mass of the 12 heavy pennies. He expressed this average as $3.0828\ \mathrm{g} \pm 0.0482\ \mathrm{g}.$ What is wrong with the numbers in this result, and how should the value be expressed?

The radius of a neon atom is $69 \mathrm{pm}$, and its mass is $3.35 \times$ $10^{-23} \mathrm{~g}$. What is the density of the atom in grams per cubic centimeter $\left(\mathrm{g} / \mathrm{cm}^3\right)$ ? Assume the atom is a sphere with volume $=\frac{4}{3} \pi r^3$.

You are driving $65~\mathrm{mph}$ and take your eyes off the road “just for a second.” How many feet do you travel in this time?

Round off each of the following numbers to the indicated number of significant digits, and write the answer in standard scientific notation. 0.00034159 to three digits

A cylindrical rod formed from silicon is $16.8 \mathrm{~cm}$ long and has a mass of $2.17 \mathrm{~kg}$. The density of silicon is $2.33 \mathrm{~g} / \mathrm{cm}^3$. What is the diameter of the cylinder? (The volume of a cylinder is given by $\pi r^2 h$, where $r$ is the radius, and $h$ is its length.)

The density of an irregularly shaped object was determined as follows. The mass of the object was found to be $28.90 \mathrm{g} \pm0.03 g.$ A graduated cylinder was partially filled with water. The reading of the level of the water was $6.4 \mathrm{cm}^{3} \pm 0.1 \mathrm{cm}^{3}.$ The object was dropped in the cylinder, and the level of the water rose to $9.8 \mathrm{cm}^{3} \pm 0.1 \mathrm{cm}^{3}.$ What is the density of the object with appropriate error limits?

The radius of a neon atom is 69 pm, and its mass is $3.35 \times 10^{-23}\ \mathrm{g}.$ What is the density of the atom in grams per cubic centimeter $\left(\mathrm{g} / \mathrm{cm}^{3}\right) ?$ Assume the nucleus is a sphere with volume $=\frac{4}{3} \pi r^{3}.$

Many times errors are expressed in terms of percentage. The percent error is the absolute value of the difference of the true value and the experimental value, divided by the true value, and multiplied by 100. Percent error $=\frac{| \text { true value }-\text { experimental value } |}{\text { true value }} \times 100.$ Calculate the percent error for the following measurements. The experimental determination of iron in iron ore was 16.48%. (True value 16.12%.)