Assume that an electron in an atom can be treated as if it were confined to a box of width 2.0 $\mathrm{\text{\AA}}$ . What is the ground state energy of the electron? Compare your result to the ground state kinetic energy of the hydrogen atom in the Bohr’s model of the hydrogen atom.

Apply the chi-square goodness-of-fit test, using either the critical-value approach or the P-value approach, to perform the required hypothesis test. According to the U.S. Census Bureau publication Demographic Profiles, a relative-frequency distribution of the U.S. resident population by region in 2000 was as follows.

$$\begin{array}{l|cccc} \hline \text { Region } & \text { Northeast } & \text { Midwest } & \text { South } & \text { West } \\ \hline \text { Rel. freq. } & 0.190 & 0.229 & 0.356 & 0.225 \\ \hline \end{array}$$

A simple random sample of this year’s U.S. residents gave the following frequency distribution.

$$\begin{array}{l|cccc} \hline \text { Region } & \text { Northeast } & \text { Midwest } & \text { South } & \text { West } \\ \hline \text { Frequency } & 45 & 42 & 92 & 71 \\ \hline \end{array}$$

a. Identity the population and variable under consideration here. b. At the 5% significance level, do the data provide sufficient evidence to conclude that this year’s resident population distribution by region has changed from the 2000 distribution?

Meat consumption in the United States can be broken into three categories: red meat, poultry, and fish. If fish makes up 4% less than one-quarter of poultry consumption, and red meat consumption is 18.2% higher than poultry consumption, what are the percentages of meat consumption?

Meat consumption in the United States can be broken into three categories: red meat, poultry, and fish. If fish makes up $4 \%$ less than one-quarter of poultry consumption, and red meat consumption is $18.2 \%$ higher than poultry consumption, what are the percentages of meat consumption?

The majority of all plants are seed plants. What is the advantage of a seed? How do plants that lack seeds meet the needs served by seeds?

Explain the following statement:

Carbon dioxide escapes from the solution when the cap is removed from a carbonated soft drink bottle.

When $6 \mathrm{~g}$ of granulated $\mathrm{Zn}$ is added to a solution of $2 \mathrm{M} \mathrm{HCl}$ in a beaker at room temperature, hydrogen gas is generated. For each of the following changes (at constant volume of the acid), state whether the rate of hydrogen gas evolution will be increased, decreased, or unchanged:
$2 M$ acetic acid is used instead of $2 \mathrm{M} \mathrm{HCl}$.

Underline the appositive or appositive phrase in each sentence. Some people prefer soft pretzels, large pretzels that are warmed, to ordinary pretzels.

How do you calculate the net worth of a bank?

Full in the blank so that the resulting statement is true.

The set of elements common to both $(-\infty, 9)$ and $(-\infty, 12)$ is $\underline{\qquad\qquad}$ .

Un peu d'histoire. Etes-vous bon(ne) en histoire? Avec un(e) camarade, trouvez la date qui correspond a chaque evenement historique. Les evenements sont presentes par ordre chronologique!

Prise de la Bastille.

a. 1944

b. 1804

c. 1889

d. 1066

e. 1429

f. 1789

g. l'an 800

Use matrices A and B.

$$A=\left[\begin{array}{rr}1 & -2 \\ 0 & 3 \end{array}\right] \quad B=\left[\begin{array}{rr}-3 & 1 \\2 & -1 \end{array}\right]$$

Show that $(A+B)^2\ne A^2+2AB+B^2$

By which equation can magnetic field force on a moving particle be represented?

A miner working $260 \mathrm{~m}$ below sea level opened a carbonated soft drink during a lunch break. To his surprise, the soft drink tasted rather "flat." Shortly afterward, the miner took an elevator to the surface. During the trip up, he could not stop belching. Why?