The two hemispheres of the brain are almost separate structures except for their lower midportions, which are connected by a structure called the _____ _____.

Indicate the structures of the following molecules in terms of the overlap of simple atomic orbitals and hybrid orbitals:

$$\mathrm{OCN}^{-}$$

Draw plausible Lewis structures for
(d) phosphoric acid, $\mathrm{H}_3 \mathrm{PO}_4$;

** Explain** why nonsilicate minerals have a wider variety of crystalline structures than silicate minerals do.

Treating cyclohexene with 1,1 -diodoethane and a zinc-copper couple leads to two isomeric products. What are their structures?

Write Lewis structures for the following:

(a) $\mathrm{Ga}$
(b) $\mathrm{Ga}^{3+}$
(c) $\mathrm{Ca}^{2+}$

Draw Lewis structures for the following:

(a) $\mathrm{H}_2$
(b) $\mathrm{N}_2$
(c) $\mathrm{Cl}_2$

Propose structures and give IUPAC names for the following: (a) A dimethyloctane (b) A diethyldimethylhexane (c) A cycloalkane with three methyl groups

Draw structures to represent these four complex ions:
(b) $\left[\mathrm{FeCl}_4(\mathrm{en})\right]^{-}$;

Based on Lewis structures, predict the ordering, from shortest to longest , of N - O bond lengths in

$$NO^+, NO_2^- ,$$

and

$$NO_3^-$$

From their Lewis structures, determine the number of

$$\sigma$$

and

$$\pi$$

bonds in each of the following molecules or ions: cyanogen.

Use electron dot structures to determine formulas of the ionic compounds formed when

Potassium reacts with iodine.

4. Why may protein in the urine be a sign of kidney damage? What structures in the kidney are probably affected ?

Diagram the structure of a leaf. What structures regulate water loss and $\mathrm{CO}_2$ absorption by a leaf?