Year 9 Periodic Table Flashcards
(27 cards)
How are the element arranged?
In order of atomic (proton) number
What is the relationship between electrons and groups?
Element in the same group have the same number of electrons in the outer shell
Describe the steps of development of the periodic table
- Before the discovery of protons, neutrons and electrons, elements were arranged by weights
- Then Mendeleev overcame this and began to leave gaps for those that weren’t discovered.
- Finally knowledge of isotopes explained why this was not correct
True or false? Elements that react to form positive ions are metals
True
How are non metals formed?
Elements that do not form positive ions
Where are metals found in the periodic table?
To the left of the steps
What are group 0 called
Noble gases
State the reactivity of noble gases
Unreactive
How many electrons do noble gases have in their outer shell
8
Why are group 0 so unreactive
Their atoms have stable arrangements of electrons
How does the boiling point change through group 0
It increases lower down the group
What is group 1 known as
The alkali metals
How many electrons are in group 0 outer shell
1
How does reactivity change within group 1
It increases going down the group
How do the first three alkali metals react with oxygen
They form a metal oxide on the surface but when cut they are shiny
What happens when the first 3 alkali metals react with chlorine
They form a chloride salt
What happens when the first 3 alkali metals react with water
They form a metal hydroxide and hydrogen
What is group 7 known as
The halogens
What are the halogens
Non metals which consist of pairs of atoms
How does the reactivity of element change in group 7
It decreases down the group
How does a halogen displace another halogen
If the halogen is more reactive than another it can displace the less reactive halogen from an aqueous solution of it’s salt
How many electrons do halogens have in their outer shell
7 electrons
What colour and state is fluorine
Very reactive, poisonous yellow gas
