Chapter 5 - The Periodic Law

Question 1

What is the name for repeating patterns?

Answer 1

Periodic

Question 2

What is the periodic law?

Answer 2

The physical and chemical properties of the elements are periodic functions of their atomic numbers

Question 3

How is the modern periodic table arranged?

Answer 3

In order of atomic number so that elements with similar properties fall in the same group

Question 4

Group 1

• name
• outer electron shell description
• appearance
• reactivity
• exception

Answer 4

Alkali
1 electron in outer s orbital
Silvery appearance and soft
Very reactive
Does not include hydrogen

Question 5

Group 2

• name
• outer shell description
• reactivity

Answer 5

Alkaline-Earth
2 electrons in outer s shell
Less reactive than alkali, but still too reactive to be found pure in nature

Question 6

What group number and type of electron shell does helium have?

Answer 6

Group 18 with two valence electrons in its filled outer shell, which gives it special chemical stability

Question 7

What type of elements are in the d block?

Answer 7

Transition

Question 8

What are the elements called in the s and p blocks?

Answer 8

Main-group

Question 9

What three types fill the p block?

Answer 9

Non-metals, metals, metalliods

Question 10

What are the group 17 elements called, how reactive are they, and what do they form when they do react?

Answer 10

Halogens, most reactive of all of the nonmetals, form salts

Question 11

Where are the Metalliods?

Answer 11

Stair-step between nonmetals and metals

Question 12

What is the first row under the periodic table called and what group can they be compared to in reactivity?

Answer 12

Lanthanides, group 2

Question 13

What is the second row under the periodic table called and what is their special characteristic?

Answer 13

Actinides, all radioactive

Question 14

Who made the very first periodic table and how was it arranged?

Answer 14

Mendeleev- by average atomic mass

Question 15

How did Mendeleev know that his table was well-designed?

Answer 15

He predicted three elements that were discovered later (all before 1886). Ekaaluminum was Gallium, Ekaboron was Scandium and Ekasilicon was Germanium. He was able to predict many of their properties before they were discovered.

Question 16

Who changed the first periodic table and how did he change it?

Answer 16

Mosely discovered that the elements fit better when arranged according to atomic number

Question 17

What is the definition of the modern periodic table?

Answer 17

An arrangement of the elements in order of their atomic number so that elements with similar properties fall in the same column, or group

Question 18

What are the differences in atomic number in a group? (group 18)

Answer 18

He-Ne-Ar-Kr-Xe-Rn is 8-8-18-18-32 (they represent the different sublevels that are being filled 8=sp 18=spd 32=spdf)

Question 19

What are the general properties, name, and reactivity of the d-block elements?

Answer 19

Metallic properties, transition elements, low reactivity

Question 20

What is group 18 called and how reactive are they?

Answer 20

Noble-gases, not reactive

Question 21

How is the length of the period determined?

Answer 21

The number of electrons that can occupy the sublevels being filled in that period

Question 22

What are the four blocks of the periodic table?

Answer 22

S, P, D, and F (they are determined by the sublevel being filled

Question 23

What is the definition of atomic radius?

Answer 23

One-half the distance between the nuclei of identical atoms that are bonded together

Question 24

What are the trends of the atomic radius in the periodic table + explain?

Answer 24

They increase as you go left and down
The size of the nucleus shrinks as you go right because more protons are being added which attracts the electrons (Zee effective charge) and they grow as you go down the table because the electron cloud is growing as sublevels are added

Question 25

What is an ion?

Answer 25

An atom of group of bonded atoms that has a positive or negative charge

Question 26

What is ionization energy (or first ionization energy)?

Answer 26

The energy required to remove one electron from a neutral atom of an element

Question 27

What are the trends of ionization energy in the periodic table + explain?

Answer 27

They increase as you go right and up
The ionization energy increases as you go right because more protons are being added which attracts the electrons (Zee effective charge) and they grow as you go up the table because the electron cloud is shrinking as sublevels are removed (bigger cloud = easier to remove)

Question 28

What is electron affinity?

Answer 28

The energy change that occurs when an electron is acquired by a neutral atom

Question 29

What are the trends of electron affinity in the periodic table + explain?

Answer 29

They increase as you go right and up
The electron affinity increases as you go right because more protons are being added which attracts the electrons (Zee effective charge) and they grow as you go up the table because the electron cloud is shrinking as sublevels are removed (bigger cloud = easier to remove)

Question 30

What is a cation?

Answer 30

A positive ion formed by the loss of one or more electrons

Question 31

How does the formation of a cation change the atom (size) and why?

Answer 31

The atom (radius) shrinks; the remaining electrons are attracted more by the unbalanced positive charge

Question 32

What is a anion?

Answer 32

A negative ion formed by the addition of one or more electrons

Question 33

How does the formation of a anion change the atom (size) and why?

Answer 33

The atom (radius) grows; the greater electron repulsion causes the electrons to spread out more

Question 34

What are the trends of ionic radius in the periodic table + explain?

Answer 34

They increase as you go left and down
The size of the nucleus shrinks as you go right because more protons are being added which attracts the electrons (Zee effective charge) and they grow as you go down the table because the electron cloud is growing as sublevels are added

Question 35

What are valence electrons?

Answer 35

The electrons available to be lost, gained, or shared in the formation of chemical compounds

Question 36

What is electronegativity?

Answer 36

A measure of the ability of an atom in a chemical compound to attract electrons from another atom in the compound

Question 37

What are the trends of electronegativity in the periodic table?

Answer 37

They tend to increase across periods and decrease or remain the same down a group