Topic 6 - Groups in the Periodic Table Flashcards
Why do the elements in Group 1 have similar chemical properties?
They all have 1 outer electron
What is Group 1 called?
Alkalai Metals
What are the Group 1 Physical Properties
Low melting and boiling points ( comp to other metals)
Very soft
What bonds do Group 1 elements form?
Ionic, no covalent bonds
Why doesnt group 1 form covalent bonds?
They only have 1 outer electron so it is lost very easily, there is no point of sharing it
What ions do group 1 form?
+1
What makes a metal reactive?
the more readily a metal looses their outer electrons, this makes group 1 ( with only 1 outer electron ), very reactive
Why are metals more reactive with water ( or dilute acid ) as you go down a group?
Their outer electrons are further out, having more shells in between them. This makes the electron less strongly bonded the the nucleus and less energy is needed to remove it.
What happens and forms when Alkali Metals (group 1) react with water?
A hydroxide and a hydrogen gas
They react vigorously, forming an ionic compound
Write the balanced equation for sodium reacting with cold water
2Na + 2H₂O –> 2NaOH + H₂
Sodium + water —> Sodium hydroxide + water
Lithium’s reaction with water
Observations
Move around the surface, Fizzing furiously
Sodium and Potassium reactions with water.
Same as lithium, but they also melt in the heat of the reaction.
Potassium often gets hot enough to ignite the hydrogen produced.
WHat are group 7 elements known as?
Halogens
Why do group elements have similar properties?
They all have the same number of outer electrons
How do halogens exist chemically?
In Diatonic Molecules, sharing one pair of electrons in a covalent bond giving both atoms a full outer shell
How do the physical properties of Group 7 elements change across the group?
The melting and boiling points increase as you go down the group
Why do the melting/boiling points increase as you go down group 7 molecules?
The Molecules get bigger due to more shells, this creates stronger intra-molecular forces meanign more energy is needed to break them apart
What is Chlorine at room temperature?
a fairly reactive, poisonous, green GAS
What is Bromine at room temperature?
a poisonous red-brown liquid, which gives off an orange vapour at room temperature.
What is iodine at room temperature?
a dark grey crystalline solid which gives off a purple vapour when heated.
How do you test a gas for Chlorine?
Damp Blue Litmus Paper
- Chlorine will bleach the litmus paper, turning it white.
- ( it may turn it red first as it is acidic)
How does reactivity work in Group 7?
It is less as you go down the group.
Halogens need to gain an electron, as more shells are gained the attraction to the nucleus is less, making it harder to attract and electron.
What makes a Halogen more/less reactive?
the Easier it is to attract an electron
What is the reaction of Halogens with metals?
Halogen + Metal –> Metal Halide (Salt)
