In a molecule of H_{2}, the four electron groups around the sulfur atom are arranged in a tetrahedral geometry. However, the shape of the molecule is called bent. Why does the shape of the molecule have a different name from the name of the electron group geometry?

Predict the shape of a molecule with each of the following:

a. Two bonded atoms and no lone pairs

b. Three bonded atoms and one lone pair

Draw resonance structures for each of the following molecules or ions: a. $\mathrm{HCO}_2^{-}(\mathrm{C}$ is the central atom $)$ b. $\mathrm{N}_2 \mathrm{O}$

Draw resonance structures for each of the following molecules or ions: a. $\mathrm{ClNO}_2$ ( $\mathrm{N}$ is the central atom) b. $\mathrm{OCN}^{-}(\mathrm{C}$ is the central atom)

Draw the electron-dot formula for each of the following molecules or ions: a. $\mathrm{HCCH}$ (ethyne) b. $\mathrm{CS}_2$ c. $\mathrm{NO}^{+}$

How many kilojoules are released when $75.0 \mathrm{~g}$ of steam at $100{ }^{\circ} \mathrm{C}$ condenses, cools to $0^{\circ} \mathrm{C}$, and freezes? (Hint: The solution will require three energy calculations.)

Draw the electron-dot formula for $\mathrm{Cl}_2 \mathrm{O}$.

Determine the total number of valence electrons for each of the following: a. $\mathrm{H}_2 \mathrm{~S}$ b. $\mathrm{I}_2$ c. $\mathrm{CCl}_4$ d. $\mathrm{OH}^{-}$

Two parallel square plates 30 cm on a side are separated by a distance of 15 cm but the edge of the lower plate lies halfway between the edges of the top plate. Find the shape factor for this geometry.

In a propane molecule with three carbon atoms, what is the geometry around each carbon atom?

What can you conclude by using the given statement together with each additional statement? If no conclusion is possible, say so.

Given: All my students love geometry.

Luis loves geomelry.

How does hyperbolic geometry differ from Euclidean geometry?

State Euclid's assumption about parallel lines that no longer applies in hyperbolic and elliptic geometry.

In spherical geometry, all points are points on the surface of a sphere. A line is a circle on the sphere whose diameter is equal to the diameter of the sphere. In spherical geometry, do you think that two triangles are congruent if their corresponding sides are congruent? Justify your answer.