Ch. 7 Periodic Properties Of The Elements

Question 1

Valence orbitals

Answer 1

the occupied orbitals that hold the electrons involved in bonding.

Question 2

Which two Scientists Published almost identical versions of the periodic table in 1869?

Answer 2

• Dmitri Mendeleev, Russia
• Lothar Meyer, Germany
• Mendeleev is given credit for advancing his ideas more vigorously and stimulating new work.

Question 3

Who developed the concept of atomic numbers?

Answer 3

Henry Moseley in 1913

• English Physicist
• Changed the periodic table that was originally based off of atomic weights.

Question 4

Coulomb’s law tells us what?

Answer 4

the strength of the interaction between two electrical charges depends on the magnitudes of the charges and on the distance between them.

Question 5

Zeff

Answer 5

effective nuclear charge

-view of a net electric field as if it results from a single positive charge located at the nucleus.

Question 6

Zeff >, =, or < Z

Answer 6

The effective nuclear charge is < actual nuclear charge.

Zeff<Z

Question 7

The number of protons in the nucleus is represented by what?

Answer 7

Z, atomic number

Question 8

S represents what

Answer 8

• “the screening constant”
• represents the portion of the nuclear charge that is screened from a valence electron by the other electrons from the nucleus.
• Value of S is normally close to the number of core electrons in an atom.

Question 9

How do you calculate Zeff

Answer 9

Zeff= Z-S
Zeff= number of protons - number of core electrons

Question 10

Zeff will increase from ____ to ____, and ____ to ____.

Answer 10

Zeff increases

• From Left to Right
• From Top to Bottom
• Much greater increase from L to R in comparison to T to B.