Chapter 11

What do those in the field of chemistry study?

Name the five major divisions of chemistry

If a salad dressing is poured on a salad, what kind of mixture results?

What characteristic distinguishes an element from a compound?

What type of process is involved in going from elements to compounds, and vice versa?

Give one example each of a solid solution, a liquid solution, and a gaseous solution.

When sugar is dissolved in iced tea, what is the solvent and what is the solute? When would you become aware that the solution was saturated?

About how many elements are known at present? About how many occur naturally in our environment?

Name the two elements that predominate in (a) the Earth's crust, (b) the Earth's core, (c) the human body, and (d) the air. In each case, list the more predominant element first.

What are the shapes of the three allotropes of carbon?

Name the scientist who receives the major credit for the development of the periodic table. In what year was his work published?

At first, the periodic table placed the elements in order of increasing atomic mass. What property is now used instead of atomic mass?

What characteristics of the elements are periodic? There are at least five.

What formal term is applied to (a) the horizontal rows of the periodic table, and (b) the vertical columns?

Why are chemists so interested in the number of valence electrons in atoms?

How do metals differ from nonmetals with regard to (a) number of valence electrons, (b) conductivity of heat and electricity, and (c) phase?

How does metallic character change (a) across a period and (b) down a group?

What are semimetals? What are their properties and what industry are they primarily used for?

List the two elements that are liquids and the five (other than the six noble gases) that are gases at room temperature and atmospheric pressure.

How does the size of atoms change (a) across a period and (b) down a group?

What are the most common names for these compounds and ions, \(\mathrm{NH}_{3}, \mathrm{HCl}, \mathrm{OH}^{-}, \mathrm{SO}_{4}^{2-} ?\)

Distinguish between (a) an atom and a molecule, (b) an atom and an ion, and (c) a molecule and a polyatomic ion.

When naming binary compounds, why must you be able to tell whether an element is a metal or a nonmetal?

Briefly, why do elements in a given group have similar chemical properties?

What are the interesting properties of noble gases? How are noble gases used in lighting?

Name the four common halogens and tell the normal phase of each. Which one is the most reactive of all elements?

Explain why sodium iodide is added to table salt.

What is the formula for the common household compound known as baking soda?

List some common uses for alkaline earth metals and their compounds.

What properties of hydrogen make it very useful in chemistry?