The "er" sound cart be spelled with er, ar, or or. For example, in squalor, or spells the "er" sound. When you are uncertain about the spelling of a word with the "er" sound, consult a dictionary. Complete the spelling of the word pall__r.

Which of these elements has chemical properties the most similar to those of chlorine $(\mathrm{Cl}$, atomic number $17$) ? (a) $\mathrm{O}$ (b) $\mathrm{Na}$ $(c)$ $S$ (d) Ar (e) $\mathrm{Br}$

Rank the following from smallest to greatest radius:

$$\begin{array}{lllll}\mathrm{K}^{+} & \mathrm{Ca}^{2+} & \mathrm{Cl}^{-} & \mathrm{S}^{2-} & \mathrm{Ar} \\ \text { Explain. }\end{array}$$

Use De Moivre's theorem to change the giver complex number to the form a+bi, where a and b ar real numbers.

$$\left(\dfrac{\sqrt{2}}{2}+\dfrac{\sqrt{2}}{2}i\right)^{25}$$

Which of the following samples would contain the largest number of atoms ? (a) $10.0 \mathrm{~g} \mathrm{He}$ (c) $10.0 \mathrm{~g} \mathrm{Ca}$ (b) $10.0 \mathrm{~g} \mathrm{Ar}$ (d) $10.0 \mathrm{~g} \mathrm{Ba}$

Identify the major attractive force between each of the following atoms or molecules:

a. $\text{SiH}_{4}$

b. $\text{NO}_{2}$

c. $\text{CH}_{3}-\text{NH}_{2}$

d. Ar

How many moles of atoms are in each elemental sample? (a) $1.34 \mathrm{~g} Z \mathrm{n}$ (b) $24.9 \mathrm{~g} \mathrm{Ar}$ (c) $72.5 \mathrm{~g} \mathrm{Ta}$ (d) $0.0223 \mathrm{~g} \mathrm{Li}$

Identify each solid as molecular, ionic, or atomic.

(a) $\operatorname{Ar}(\mathrm{s})$

(b) $\mathrm{H}_2 \mathrm{O}$ (s)

(c) $\mathrm{K}_2 \mathrm{O}(\mathrm{s})$

(d) $\mathrm{Fe}(\mathrm{s})$

Write the name of the element for each symbol. a. $\mathrm{C}$ b. $\mathrm{Cl}$ c. I d. $\mathrm{Hg}$ e. $\mathrm{Ag}$ f. $\mathrm{Ar}$ g. $\mathrm{B}$ h. $\mathrm{Ni}$

What is the amount, in moles, of each elemental sample?
a. $11.8 \mathrm{~g}$ Ar
b. $3.55 \mathrm{~g} \mathrm{Zn}$
c. $26.1 \mathrm{~g}$ Ta
d. $0.211 \mathrm{~g} \mathrm{Li}$

Arrange these quantities from smallest to largest in terms of mass: 1.0 mol of $\mathrm{Ar}_{\text {t }}$ $3.0 \times 10^{24}$ atoms of Ne, and 20 g of Kr.

Write the rate law for each of the following elementary reactions:
(a) $\mathrm{O}_3(g)+\mathrm{O}(g) \longrightarrow 2 \mathrm{O}_2(g)$
(b) $\mathrm{Br}(g)+\mathrm{Br}(g)+\operatorname{Ar}(g) \longrightarrow \mathrm{Br}_2(g)+\operatorname{Ar}(g)$
(c) $\mathrm{Co}(\mathrm{CN})_5\left(\mathrm{H}_2 \mathrm{O}\right)^{2-}(a q) \longrightarrow \mathrm{Co}(\mathrm{CN})_5{ }^{2-}(a q)+\mathrm{H}_2 \mathrm{O}(l)$

The "er" sound cart be spelled with er, ar, or or. For example, in squalor, or spells the "er" sound. When you are uncertain about the spelling of a word with the "er" sound, check it in a dictionary. Complete the spelling of the word coll__r.

Completa las oraciones con g o j.

Nadie contradi ____ o a la ____ efa cuando anunció que era ur ____ ente fi ____ ar otra fecha limite para el proyecto.