Ionic and Molecular Compounds

Identify the error in each of the following Lewis structures and draw the correct formula:$\left(6.6\right)$

a. 

b.

c.

Predict the shape of each of the following molecules: $(6.8)$

a. $N{H}_{2}Cl (N is the central atom)$

b. $Te{O}_2$

Classify each of the following molecules as polar or nonpolar:$\left(6.7 ,6.8 ,6.9\right)$

a. $N_2$

b. $N{H}_{2}Cl$

For parts a to f, consider the loss of electrons by atoms of the element $X$, and a gain of electrons by atoms of the element $Y$, if $X$ is in Group $2A\left(2\right)$, Period $3$, and $Y$ is in Group $7A \left(17\right)$, Period $3$. ($4.6, 6.1, 6.2, 6.3, 6.8$)

a. Which reactant has the higher electronegativity? 

b. What are the ionic charges of $X$ and $Y$ in the product?

c. Write the electron arrangements for the atoms $X$ and $Y$.

d. Write the electron arrangements for the ions of $X$ and $Y$.

e. Give the names for the noble gases with the same electron arrangements as each of these ions.

f. Write the formula and name for the ionic compound formed by the ions of $X$ and $Y$.

A sterling silver bracelet, which is $92.5\%$ silver by mass, has a volume of $25.6 c{m}^3$ and a density of $10.2 g/c{m}^3$. ($2.10, 4.5, 5.2, 5.4$)

Sterling silver is $92.5\%$ silver by mass.

a. What is the mass, in kilograms, of the bracelet?

b. Determine the number of protons and neutrons in each of the two stable isotopes of silver:

${}_{47}{}^{107}\mathrm{Ag}$   ${}_{47}{}^{109}\mathrm{Ag}$

c. $\mathrm{Ag}-112$ decays by beta emission. Write the balanced nuclear equation for the decay of $\mathrm{Ag}-112$.

d. A $64.0-\mu Ci$ sample of $\mathrm{Ag}-112$ decays to $8.00 \mu Ci$ in $9.3 h$. What is the half-life of $\mathrm{Ag}-112$?

The naturally occurring isotopes of silicon are listed in the following table: ($4.5, 4.6, 5.2, 5.4, 6.6, 6.7$)

a. Complete the table with the number of protons, neutrons, and electrons for each isotope listed:

b. What is the electron arrangement of silicon? 

c. Which isotope is the most abundant, if the atomic mass for Silicon is $28.09$?

d. Write the balanced nuclear equation for the beta decay of the radioactive isotope $\mathrm{Si}-31$.

e. Draw the Lewis structure and predict the shape of ${\mathrm{SiCl}}_4$ 

f. How many hours are needed for a sample of $Si-31$ with an activity of $16 \mu Ci$ to decay to $2.0 \mu Ci$?

$K^{+}$ is an electrolyte required by the human body and found in many foods as well as salt substitutes. One of the isotopes of potassium is potassium-$40$, which has a natural abundance of $0.012\%$ and a half-life of $1.30\times {10}^{9 }\mathrm{yr}$. The isotope potassium-$40$ decays to calcium$‐40$ or to argon-$40$. A typical activity for potassium-$40$ is $7.0 \mathrm{\mu Ci}$per gram.$(5.2 ,5.3 , 5.4)$

Potassium chloride is used as a salt substitute.

a. Write a balanced nuclear equation for each type of decay and identify the particle emitted.

b. A shaker of salt substitute contains $1.6 \mathrm{oz}$of $K$. What is the activity, in millicuries and becquerels, of the potassium in the shaker?