Ch13 The Periodic Table

Question 1

Define periodic table:

Answer 1

A table of elements arranged in order of increasing proton number (atomic number) to show the similarities of the chemical elements with related electronic configurations.

Question 2

Define groups:

Answer 2

Vertical columns of the periodic table containing elements with similar chemical properties
Atoms of elements in the same group have the same number of electrons in their outer energy levels

Question 3

Define period:

Answer 3

A horizontal row of the periodic table

Question 4

Which 2 groups are the reactive metals?

Answer 4

Group I - alkali metals
Group II - alkaline earth metals

Question 5

What are the transition elements?

Answer 5

Strong, hard, dense metals

Question 6

What group is the non-metals?

Answer 6

Group VII - the halogens

Question 7

What group is the Noble Gases?

Answer 7

Group VIII

Question 8

To what group does hydrogen belong to?

Answer 8

No group

Question 9

Define Metalloid (semi-metal):

Answer 9

Element that shows some of the properties of metals and some of non-metals
Ex. boron, silicon

Question 10

Define main-group elements:

Answer 10

The elements in the outer groups of the periodic table, excluding the transition elements. (Groups I-VIII)

Question 11

Define transition elements (transition metals):

Answer 11

Elements from the central region of the periodic table – they are hard, strong, dense metals which form compounds that are often coloured

Question 12

Define periodic property:

Answer 12

A property of the elements that shows a repeating pattern when plotted against proton number (Z)

Question 13

Define noble gases:

Answer 13

Elements in group VIII - a group of stable, very unreactive gases

Question 14

Define halogens:

Answer 14

Elements in group VII of the periodic table - generally the most reactive group of non-metals

Question 15

Define halides:

Answer 15

Compounds formed between an element and a halogen

Question 16

Define halogen displacement reactions:

Answer 16

Reactions in which more reactive halogen displaces a less reactive halogen from a solution of its salt

Question 17

Define oxidation number:

Answer 17

A number given to show whether an element has been oxidised or reduced
The oxidation number of a simple ion is simply the charge on the ion

Question 18

How many metalloids are there?

Answer 18

8

Question 19

What are the least reactive metals on the periodic table?

Answer 19

Group VIII - noble gases

Question 20

What are the most reactive elements?

Answer 20

Group I - Alkali metals
Group VII - Halogens

Question 21

Where are the more unreactive elements, metal/non-metal?

Answer 21

In the centre of the periodic table

Question 22

Why is hydrogen not part of a group?

Answer 22

It’s the smallest atom and has the most distinctive and unique properties
It does not easily fit into the trends in any one group

Question 23

What is the relationship between elements in the same group on the periodic table?

Answer 23

They have the same nr of electrons in their outer shell

Question 24

What is the relationship between the elements and periods in the periodic table?

Answer 24

The period nr shows the amount of shells of electrons that element has

Question 25

What electrons are mainly responsible for the chemical properties of any element?

Answer 25

The outer electrons

Question 26

Do the atoms of elements in the middle of a period usually form covalent or ionic compounds?

Answer 26

Covalent compounds

Question 27

Name six characteristics of the **alkali metals**, Group I

Answer 27

1) **soft** solids 2) relatively **low** melting points 3) **low** densities 4) **highly** reactive 5) **stored in oil** to prevent them reacting with the oxygen and water vapour in the air 6) when freshly cut with a knife, all these metals have a **light grey, silvery surface** → quickly tarnishes and **becomes dull**

Question 28

How do the physical properties of the alkali metals **change** as you go **down** the group

Answer 28

1) melting points/boiling points **decrease** 2) metals get **softer** 3) densities **increase**

Question 29

Does the chemical reactivity of the alkaline metals increase/decrease when you go down the group?

Answer 29

Increase

Question 30

What happens when Group I metals react with cold water?

Answer 30

They form **hydrogen** and an **alkaline solution** of the *metal hydroxide*

Question 31

How can the production of an alkaline solution be shown?

Answer 31

By adding a few drops of universal indicator to the water The solution will turn the water **purple** if an **alkali is produced**

Question 32

What **3** observations can be made to say how ** vigorous** the reaction of *Group I metals reacting with cold water* is?

Answer 32

1) the **production** of a gas 2) whether the metal **melts** on contact with the water 3) whether the gas produced is **ignited**

Question 33

Give an example of the equation a reaction between an **alkali metal** and **cold water**:

Answer 33

Sodium + **water** → sodium **hydroxide** + **hydrogen** 2Na + 2H*2*O → 2NaOH +H*2*

Question 34

Name **8** common properties of **halogens**:

Answer 34

1) **poisonous**, similar strong smell 2) **non-metals** 3) all form diatonic molecules 4) have a **valency of 1** And from **compounds w similar formulae** eg. hydrogen chloride (HCl), hydrogen bromide (HBr), hydrogen iodide (HI) 5) their **compounds with hydrogen** are usually **strong acids** when *dissolved in water* Eg. hydrochloric acid (HCl), hydrobromic acid (HBr), hydriodic acid (HI) 6) they each **produce a series of compounds** with other **elements** → **halides** Eg. chlorides, bromides, iodides 7) can **react directly** with *metals* to form **metal halides/salts** 8) all form **negative ions** carrying a **single charge** Eg. chloride ions (Cl-), bromide ions (Br-), iodide ions (I-)

Question 35

What happens to the *properties of halogens* as you go **down the group**?

Answer 35

1) boiling points **increase** 2) **physical state changes** from *gas → liquid → solid* going down the group 3) **intensity of the color** of the element **increases**, *pale → dark*