Unit 8: Periodic Trends

Question 1

Row

Answer 1

Period

Question 2

Properties of Valence Electrons (3)

Answer 2

• determines the chemical properties of the elements
• the electrons on the highest energy level
• are related to the group number of the element

Question 3

Period

Answer 3

Row

Question 4

Column

Answer 4

Group (not including transition elements)

Question 5

What is the pattern of elements in the same group?

Answer 5

they both have the same number of valence electrons

Question 6

What does the electron-dot symbol indicate?

Answer 6

the valence electrons as dots around the symbol of the element.

Question 7

What does the electron-dot symbol show?

Answer 7

the number of valence electrons an element has

Question 8

Relationship between elements of groups and electron-dot symbol

Answer 8

In a group, all the electron-dot symbols have the same number of valence electrons (dots).

ex) all elements in group 2 have 2 dots

Question 9

The three periodic trends

Answer 9

Atomic Radius, Ionization E, Electron Affinity

Question 10

Atomic Radius

Answer 10

actual size of atom measured from nucleus to valence e-’s

(Distance from nucleus to outermost shell)

Question 11

Ionization Energy

Answer 11

Energy required to overcome the attraction from the nucleus and REMOVE an e-

Question 12

Electron Affinity

Answer 12

potential energy change of the atom when an electron is added to a neutral atom to form a negative Ion

Question 13

Shielding Effect

Answer 13

trends ACROSS the periodic table usually deal with electrons being added to the SAME energy level

trends DOWN a group usually deals with adding electrons to an INCREASING number of energy levels

Question 14

Atomic Size

Answer 14

The distance from the nucleus to the valence electrons

Question 15

How is atomic size described as?

Answer 15

by using the atomic radius

Question 16

Patterns of Atomic Radius within a Group

Answer 16

atomic radius INCREASES when going DOWN a group

atomic radius DECREASES when going ACROSS a period

Question 17

The element needs to be in what state for Ionization energy to occur?

Answer 17

gas

Question 18

The _____ the radius is the _____ it is to remove an electron

Answer 18

bigger, harder

Question 19

Ionization energies of metals are…

Answer 19

low

Question 20

Ionization energies of non-metals are…

Answer 20

high

Question 21

What does an increase in Ionization energy show?

Answer 21

tells that the element is taking on the electron configuration of the nearest noble gas

(breaking into a stable gas structure)

Question 22

Metals are what kind of ion?

Answer 22

cation

Question 23

Non-metals are what kind of ion?

Answer 23

anion

Question 24

Positive Metal Cations are how large compared to the neutral atoms?

Answer 24

smaller than the neutral atoms from which they form from

Question 25

Negative Nonmetal Anions are how large compared to the neutral atoms?

Answer 25

larger than the neutral atoms from which they form from

Question 26

Electronegativity

Answer 26

ability of an atom to attract electrons from other atoms

Question 27

The more ____ the electron affinity the more __ the electron addition process is

Answer 27

negative, favourable

Question 28

What unit is electron affinity in?

Answer 28

kJ/mol

Question 29

Electron Affinity Trend

Answer 29

Metals are LOW Non-metals are HIGH

Question 30

What letter is used for representative elements?

Answer 30

A

Question 31

What are the representative elements?

Answer 31

elements from 1A to 8A

Question 32

What elements does the A represent?

Answer 32

representative elements

Question 33

What letter is used to represent transition elements?

Answer 33

B

Question 34

What letter is B used to represent?

Answer 34

transition elements

Question 35

Group numbers can also refer to (not a or b)...

Answer 35

the numbers in columns 1-18, left to right

Question 36

What are representative elements known by?

Answer 36

common names

Question 37

What common names do the groups go by?

Answer 37

1A - Alkali metals 2A - Alkaline-earth metals 3A-6A - No common names 7A - Halogens 8A - Noble Gas

Question 38

Alkali Metals

Answer 38

Group 1A (1) which includes lithium, sodium, and potassium and forms a basic solution

Question 39

Where are metals located?

Answer 39

left

Question 40

Where are non-metals located?

Answer 40

right

Question 41

Where are semi-metals located?

Answer 41

located along the heavy zigzag line between the metals and nonmetals

Question 42

Properties of Metals

Answer 42

shiny and ductile (can bend into shapes) are GOOD conductors of heat and electricity

Question 43

Properties of Nonmetals

Answer 43

dull, brittle (crack/break easily) POOR conductors of heat and electricity

Question 44

Properties of Metalloids/Semimetals

Answer 44

BETTER conductors than non-metals, but NOT AS GREAT as metals used as semiconductors and insulators

Question 45

The metalloids section in the periodic table

Answer 45

B, Si, Ge, As, Sb, Te, Po, At