Chapter 6

Metalloid Properties

-depending on the conditions, they can have either metal or nonmetal properties

Nonmetal Properties

-gases at room temperature -poor conductors -brittle

Metal Properties

-good conductors -high luster -all metals are solid at room temperature, except mercury(Hg) -ductile(can be drawn into wires) -malleable(can be hammered into thin sheets without breaking)

Group 1 / 1A

Alkali Metals n s^1 Properties- soft, highly reactive, not found free in nature

Group 2 / 2A

Alkaline Earth Metals n s^2 Properties- harder, more dense, higher melting points, not found free in nature

16. How does atomic size change within groups and across periods?

Atomic size increases from top to bottom within a group and decreases from left to right across a period.

12. Why do the elements potassium and sodium have similar chemical properties?

Both of these elements are in the same family, alkali metals, and they have s^1 in their electron configuration.

19. Compare the size of ions to the size of the atoms from which they form.

Cations are always smaller than the atoms from which they form. Anions are always larger than the atoms from which they form.

1. How did the chemists begin the process of organizing elements?

Chemists used the properties of elements to sort them into groups.

14. Which of the following elements are transition metals: Cu, Sr, Cd, Au, Al, Ge, Co?

Cu, Cs, Au, Co

Which subatomic particle plays the key role in determining the properties of elements?

Electron

11. Into what four classes can elements be sorted based on their electron configurations

Elements can be sorted into noble gases, representative elements, transition metals, or inner transition metals based on their electron configuration.

What was the basis for Mendeleev's table of the elements?

Groups of elements share similar properties

Group 17 / 7A

Halogens n s^2 p^5 Properties- highly reactive

3. How are elements arranged in the modern periodic table?

In the modern periodic table, elements are arranged in order of increasing atomic number.

7. Name two elements that have properties similar to those of the element sodium.

Lithium and Rubidium

2. What property did Mendeleev use to organize his periodic table?

Mendeleev arranged the elements in his periodic table in order of increasing atomic masses.

4. Name the three broad classes of elements.

Metals, Metalloids, Nonmetals

Group 18 / 8A

Noble Gases n s^2 p^6 Properties- inert, unreactive, full outer shell

18. What happens to first ionization energy within groups and across periods?

Tends to decrease from top to bottom within a group and increase from left to right across a period.

10. What information can be included in a periodic table?

The periodic table displays the symbols and names of the elements, along with information about the structure of their atoms.

21. In general, how can the periodic trends displayed by elements be explained?

The trends that exist among these properties can be explained by variations in atomic structure.

Groups 3-12 / 3B-8B

Transition Metals n 4s^2d^1-10 Properties- good conductors, forms color compounds, shiny and usually hard

20. How does electronegativity vary within groups and across periods

Values decrease from top to bottom within a group. For representative elements, the values tend to increase from left to right across a period.

Periodic Law

When elements are arranged in order of increasing atomic number, there is a periodic repetition of their physical and chemical properties.

6. Identify each element as a metal, metalloid, or nonmetal. a. gold b. silicon c. sulfur d. barium

a. gold- metal b. silicon- metalloid c. sulfur- nonmetal d. barium- metal

Anion

an ion with a negative charge

Cation

an ion with a positive charge

5. Which of these sets of elements have similar physical and chemical properties? a. oxygen, nitrogen, carbon, boron b. strontium, magnesium, calcium, beryllium c. nitrogen, neon, nickel, niobium

b. strontium, magnesium, calcium, beryllium This is because these four elements are in the same group or family. They are in the alkaline earth metals.

What modification did Henry Moseley make the Mendeleev's tables?

introduced arrangement according to increasing nuclear charge

Ion

is an atom or group of atoms that has a positive or negative charge

Atomic Radius

is one half of the distance between the nuclei of two atoms of the same element when the atoms are joined

Electronegativity

is the ability of an atom to attract electrons when the atom is in a compound

Identify the sublevel "blocks" on the periodic table.

s, p, d, f

15. How many electrons are in the highest occupied energy level of a Group 5A element?

s^2 p^5

Ionization Energy

the energy required to remove an electron from an atom

17. When do ions form?

when an atom gains or loses an electron