1.6 Periodic Table

Question 1

Features of Mendeleev’s periodic table and date

Answer 1

Fewer elements as it had gaps for undiscovered elements (enabling him to predict the properties of undiscovered elements (noble gases hadn’t been discovered yet))
Arranged in order of atomic mass
No block of transition metals
No noble gases
No actinides or lanthanides
Published 1869

Question 2

Features of the modern day periodic table

Answer 2

More elements with no gaps
Arranged in order of atomic number
Block of transition metals
Noble gases
Actinides and lanthanides

Question 3

Group

Answer 3

A vertical column in the periodic table

Question 4

Period

Answer 4

A horizontal row in the periodic table

Question 5

Elements in the same group…

Answer 5

Have the same number of electrons in their outer shell, meaning they also have similar chemical properties

Question 6

Groups that have elements of similar chemical properties

Answer 6

Group 1 alkali metals (reactive)
Group 2 alkaline Earth metals (reactive)
Group 7 halogens (reactive non metals)
Group 8 noble gases (unreactive non metals)

Question 7

Where are metals and non metals on the periodic table

Answer 7

To the left of the black line are metals
To the right of the black line are non metals

Question 8

Properties of metals

Answer 8

Conduct heat and electricity
Malleable and ductile
High melting point
Sonorous

Question 9

Properties of non metals

Answer 9

Doesn’t conduct heat or electricity
Not malleable and ductile
Low melting point
Not sonorous

Question 10

Elements which occur as gases at room temperature (11)

Answer 10

Hydrogen, nitrogen, fluorine, chlorine, helium, neon, argon, krypton, xenon and radon

Question 11

Elements which occur as liquids at room temperature (2)

Answer 11

Bromine and Mercury

Question 12

Group 1 info

Answer 12

Alkali metals
Very reactive, more reactive than group 2
Have a low density (first three are less dense than water Li, Na and K so they float)
Stored under oil to prevent it reacting with moisture/oxygen in the air
Soft and easily cut, exposing a shiny surface, but tarnish rapidly in air
Forms an ion with charge of + eg Na —> Na+ + e-

Question 13

Why do alkali metals have similar chemical properties

Answer 13

When they react an atom loses an electron to form a positive ion with a stable electronic configuration

Question 14

Group 1 elements as they move further down the group

Answer 14

Low melting points decrease
Atoms increase in size
Increasingly reactive

Question 15

Why do group 1 metals get more reactive further down the group

Answer 15

The size of the atom increases down the group, meaning the outer electron to be lost is further away from the attractive positive charge of the nucleus and can be easily lost

Question 16

Group 1 metals reaction with water

Answer 16

Forms a metal hydroxide (in solution) and hydrogen eg sodium + water = sodium hydroxide + hydrogen

These reactions are highly dangerous as these metals are all highly reactive. They are stored under oil to prevent them reacting with moisture and oxygen in the air

Question 17

Lithium reaction with water

Answer 17

Group 1 metal

Metal floats, moves about the surface, fizzes/releases a gas, eventually disappears, heat released, colourless solution forms

Question 18

Sodium reaction with water

Answer 18

Group 1 metal

Metal floats, melts into a silver ball, moves about the surface, fizzes/releases a gas, eventually disappears, heat released, colourless solution forms

Question 19

Potassium reaction with water

Answer 19

Group 1 metal

Metal floats, moves about the surface, burns with a lilac flame, fizzes/releases a gas, eventually disappears, heat released, small explosion/crackle, colourless solution forms

Question 20

Group 7 info

Answer 20

Reactive non metals
Coloured
Toxic
Exist as diatomic molecules
Does not conduct electricity
Forms a simple halide ion with a charge of -
React with group 1 metals to form solid, white, ionic compounds

Question 21

Group 7 elements going down the group

Answer 21

Reactivity decreases down the group

Question 22

Fluorine at room temperature

Answer 22

Group 7 non metal
Yellow gas

Question 23

Chlorine at room temperature

Answer 23

Group 7 non metal
Yellow-green gas

Question 24

Bromine at room temperature

Answer 24

Group 7 non metal
Red-brown liquid

Question 25

Iodine at room temperature

Answer 25

Group 7 non metal Grey-black solid

Question 26

Sublimation

Answer 26

The change of state from solid directly to gas on heating, skipping liquid state

Question 27

Sublimation of iodine

Answer 27

Group 7 non metal A grey-black solid at room temperature/pressure. When heated it sublimes and the solid changes into a purple vapour. On cooling forms grey-black crystals

Question 28

Test for chlorine gas

Answer 28

Group 7 non metal Damp universal indicator paper changes to red and bleaches white in the presence of chlorine

Question 29

What does chlorine displace

Answer 29

Chloride ions XX Bromide ions (colourless solution turns orange) Iodide ions (colourless solution turns brown)

Question 30

What does bromine displace

Answer 30

Chloride ions (no reaction) Bromide ions XX Iodide ions (orange solution turns brown)

Question 31

What does iodine displace

Answer 31

Chloride ions (no reaction) Bromide ions (no reaction) Iodide ions XX

Question 32

Why do group 7 elements have similar chemical properties

Answer 32

Their atoms have seven electrons in their order shells. When they react, they gain an electron to form a negative ion with a stable electronic configuration

Question 33

Chlorine atom and chlorine molecule half equations

Answer 33

Cl + e- = Cl- Cl2 + 2e- = 2Cl-

Question 34

Why does reactivity decrease down group 7

Answer 34

Atom size increases down the group. The atoms gains the electron less readily due to the distance of the outer shell from the attractive positive charge of the nucleus. Electrons gained in shells close to the nucleus gain very readily. In larger atoms inner electrons shield the incoming electron from the attractive positive charge of the nucleus

Question 35

Group 0 info

Answer 35

Unreactive non metals Noble gases are colourless Group 0 elements do not have a valency because they have a full outer shell of electrons. This makes them stable and unreactive

Question 36

Group 0 elements going down the group

Answer 36

Boiling points increase due to the increasing strength of van def Waals forces between atoms

Question 37

Where are transition metals found on the periodic table

Answer 37

The block of elements between groups 2 and 3

Question 38

Transition metals properties in comparison to group 1’s elements

Answer 38

Have higher melting points (except Mercury) Have higher density Much less reactive with water Form ions with different charges (eg iron ii and iron iii) Form coloured compounds

Question 40

Examples of coloured compounds formed by transition metals

Answer 40

Copper (ii) oxide = black Copper (ii) carbonate = green Hydrated copper (ii) sulfate = blue Copper (ii) sulfate = blue IN SOLUTION