The Periodic Table, Periodic Trends, and E-Configurations

The Periodic Table, Periodic Trends, and e-configurations

Definitions and Direction of 4 Periodic Trends:

A. Electronegativity –

Trend: down a group ______across a period ______

B. Ionization energy –

Trend: down a group ______across a period ______

C. Atomic radius –

Trend: down a group ______across a period ______

D. Ionic radius –

Trend for positive ion: down a group ______across a period ______

Trend for negative ion: down a group ______across a period ______

Reasoning Behind Periodic Trends:

Down a group – more energy levels, electrons farther away from positive nucleus, pulled less tightly

Across a period – same energy level, but more protons, protons pull electrons in more tightly,

increased effective nuclear charge

Applying Trends:

Put the following elements in order from largest to smallest according to the specified trend.

A. Electronegativity – P, Ga, O, Ba ______

B. Ionization Energy – Cl, Mg, Si, Sr ______

C. Atomic Radii – C, Rb, F, Na ______

How does a cation’s size compare to the size of its parent atom?

Li Li+

How does an anion’s size compare to the size of its parent atom?

N N3-

Groups, Periods

1 18

1A 8A

2 13 14 15 16 17

2A 3A 4A 5A 6A 7A

______

A groups (groups 1-2, 13-18) are called the ______

B groups (groups 3-12) are called the ______

List the group number for each of the following:

alkali metals ______

alkaline earth metals ______

halogens ______

noble gases ______

How many valence electrons are in each of the following?

Na K B N O Se Cl

What is the oxidation number of each of the following?

Na K B N O Se Cl

Electron Configuration

What element?

1s1 ______1s22s22p63s23p5 ______[He]2s1 ______[Ar]4s23d8 ______

How many valence electrons?

1s2 ______1s22s22p63s23p6 ______[Ne]3s2 ______[Ar]4s23d104p3 ______

What oxidation number?

1s1 ______1s22s22p4 ______[He]2s1 ______[Ar]4s23d8 ______

Number of electrons lost or gained to make a stable ion?

1s22s22p63s23p5 ______[Ne]3s2 ______[Ar]4s23d104p3 ______

Write the electron configuration and draw the electrons for the orbital notation of NITROGEN

______

Multiple Choice

1. The element in Period 2 with the largest atomic radius is

(A) a halogen (C) an alkali metal

(B) a noble gas (D) an alkaline earth metal

2. Which sequence of atomic numbers represents elements which have similar chemical properties?

(A) 19, 23, 30, 36 (C) 3, 12, 21, 40

(B) 9, 16, 33, 50 (D) 4, 20, 38, 88

3. All of the atoms of the elements in Period 2 have the same number

(A) protons (C) valence electrons

(B) neutrons (D) occupied energy levels (shells)

4. In which classification is an element placed if the outermost 3 sublevels of its atoms have a ground state electron configuration of 3p63d54s2?

(A) alkaline earth metals (C) metalloids (semimetals)

(B) transition metals (D) nonmetals

5. Low ionization energies are most characteristic of atoms that are

(A) metals (C) metalloids

(B) nonmetals (D) noble gases

7. As the atoms of the elements in Group 1 are considered in order from top to bottom, compared to the ionization energy of the atom above it, the ionization energy of each successive atom

(A) decreases (C) remains the same

(B) increases

10. Which sequence correctly places the elements in order of increasing ionization energy?

(A) H®Li®Na®K (C) O®S®Se®Te

(B) I®Br®Cl®F (D) H®Be®Al®Ga

11. Which of the following particles has the smallest radius?

(A) Na0 (C) Na+

(B) K0 (D) K+

12. Which atom has the strongest attraction for electrons?

(A) Cl (C) Br

(B) F (C) I

13. As the elements in Group 1 are considered in order of increasing atomic number, the atomic radius of each successive element increases. This is primarily due to an increase in the number of

(A) neutrons in the nucleus

(B) electrons in the outermost shell

(D) principal energy levels (shells)

14. When a sodium atom becomes an ion, the size of the atom

(A) decreases by gaining an electron

(B) decreases by losing an electron

(D) increases by losing an electron

15. Which element has an atomic radius that is greater than its ionic radius?

(A) S (C) F

(B) K (D) O

16. Elements that readily gain electrons tend to have

(A) high ionization energy and high electronegativity

(B) high ionization energy and low electronegativity

(D) low ionization energy and high electronegativity

17. Which element in Period 3 has the greatest tendency to gain electrons?

(A) Na (C) Cl

(B) Si (D) Ar

19. Which diagram correctly shows the relationship between electronegativity and atomic number for the elements of Period 3?