Periodic Trends 6 - Springfield Public Schools - Home · Periodic Trends 6.3 © Copyright Pearson...

of 31

Periodic Trends 6.3

© Copyright Pearson Prentice Hall

Slide 2 of 31

Periodic Trends

Sodium chloride (table salt) produced the geometric pattern in the photograph. Such a pattern can be used to calculate the position of nuclei in a solid. You will learn how properties such as atomic size are related to the location of elements in the periodic table.

6.3


Periodic Trends >

Slide 3 of 31

Trends in Atomic Size

Trends in Atomic Size

What are the trends among the elements for atomic size?

6.3

of 31


Periodic Trends > Trends in Atomic Size

The atomic radius is one half of the distance between the nuclei of two atoms of the same element when the atoms are joined.

6.3

of 31


Periodic Trends > Trends in Atomic Size

Group and Periodic Trends in Atomic Size

In general, atomic size increases from top to bottom within a group and decreases from left to right across a period.

6.3

of 31


Periodic Trends > Trends in Atomic Size 6.3


Periodic Trends >

Slide 8 of 31

Ions

Ions

How do ions form?

6.3


Slide 9 of 31

Periodic Trends > Ions

Positive and negative ions form when electrons are transferred between atoms.

6.3


Slide 10 of 31


Positive and negative ions form when electrons are transferred between atoms.

6.3

of 31



Some compounds are composed of particles called ions.

• An ion is an atom or group of atoms that has a positive or negative charge.

• A cation is an ion with a positive charge.

• An anion is an ion with a negative charge.

6.3


Slide 12 of 31


Animation 7

Discover the ways that atoms of elements combine to form compounds.


Periodic Trends >

Slide 13 of 31

Trends in Ionization Energy

Trends in Ionization Energy

What are the trends among the elements for first ionization energy, ionic size, and electronegativity?

6.3

of 31


Periodic Trends > Trends in Ionization Energy

The energy required to remove an electron from an atom is called ionization energy.

• The energy required to remove the first electron from an atom is called the first ionization energy.

• The energy required to remove an electron from an ion with a 1+ charge is called the second ionization energy.

6.3

of 31


Periodic Trends > Trends in Ionization Energy

Group and Periodic Trends in Ionization Energy

First ionization energy tends to decrease from top to bottom within a group and increase from left to right across a period.

6.3

of 31


Periodic Trends > Trends in Ionization Energy 6.3


Slide 18 of 31

Periodic Trends > Trends in Ionization Energy 6.3

of 31


Periodic Trends > Trends in Ionic Size

Trends in Ionic Size

During reactions between metals and nonmetals, metal atoms tend to lose electrons, and nonmetal atoms tend to gain electrons. The transfer has a predictable effect on the size of the ions that form.

6.3

of 31



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

6.3

of 31



Relative Sizes of Some Atoms and Ions

6.3


Slide 22 of 31


Trends in Ionic Size

6.3 S

ize

gene

rally

incr

ease

s

of 31


Periodic Trends > Trends in Electronegativity

Trends in Electronegativity

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

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

6.3

of 31


Periodic Trends > Trends in Electronegativity

Representative Elements in Groups 1A through 7A

6.3


Periodic Trends >

Slide 25 of 31

Summary of Trends

Summary of Trends

What is the underlying cause of periodic trends?

6.3

of 31


Periodic Trends > Summary of Trends

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

6.3


Slide 27 of 31

Periodic Trends > Summary of Trends 6.3

Atomic Size Increases

Incr

ease

s

Decreases

Dec

reas

es

Size of cations Shielding Nuclear Charge Electronegativity Ionization energy Size of anions Ionic size Constant


Slide 28 of 31

Section Quiz

-or- Continue to: Launch:

Assess students’ understanding of the concepts in Section

Section Assessment

6.3


Slide 29 of 31

1. Which of the following sequences is correct for atomic size?

a.  Mg > Al > S

b.  Li > Na > K

c.  F > N > B

d.  F > Cl > Br

6.3 Section Quiz


Slide 30 of 31

6.3 Section Quiz

2. Metals tend to

a.  gain electrons to form cations.

b.  gain electrons to form anions.

c.  lose electrons to form anions.

d.  lose electrons to form cations.


Slide 31 of 31

6.3 Section Quiz

3. Which of the following is the most electronegative?

a.  Cl

b.  Se

c.  Na

d.  I

END OF SHOW

Periodic Trends 6 - Springfield Public Schools - Home · Periodic Trends 6.3 © Copyright Pearson...

Documents

Transcript of Periodic Trends 6 - Springfield Public Schools - Home · Periodic Trends 6.3 © Copyright Pearson...