Groups Flashcards
How are Group 1 metals similar (properties)?
Malleable and conduct electricity Low melting points Soft and easily cut Very reactive Easily oxidised
What is the rate of reactivity down the group?
Reactivity increases down the group
What happens when Lithium reacts with water?
Bubbles fiercely on the surface
What happens when sodium reacts with water?
Melts into a ball and fizzes about the surface
What happens when potassium reacts with water?
Produces a lilac flame and flies about the surface very quickly
Why do the elements get more reactive down the group?
As we go down the group, an extra electron shell is added.
This decreases the force of attraction between the positive nucleus and negative outer electron as the electron is getting further away from the nucleus
So the electron is removed more easily
What are the properties of Group 7 elements?
All halogens are diatomic molecules
Poor conductors of heat and electricity
Corrosive and toxic
What is the appearance of Chlorine?
Green gas
What is the appearance of bromine?
Brown liquid
What is the appearance of iodine?
Purple solid
Why are the halogens good bleaches/disinfectants?
They can kill microorganisms and remove the colour from materials
How is hydrogen chloride made?
Hydrogen and chlorine molecules collide causing the covalent bonds (which hold atoms together) to break
Covalent bonds form between hydrogen and chlorine atoms making hydrogen chloride
When dissolved in water, hydrogen chloride breaks up into hydrogen and chlorine ions
What is reactivity down the group?
Decreases down the group
How can the reactivity of halogens be determined by displacement reactions?
A more reactive element displaces the less reactive element in a ionic compound
Therefore, chlorine can displace bromine from sodium bromide but bromine cannot displace chlorine from sodium chloride
Why does reactivity decrease down the group?
Down the group, the elements have an extra electron shell
Therefore, the out most electrons are further away from the nucleus
So the force of attraction between the positive nucleus and and outmost electrons (and the electron about to be brought) decreases
So the ions don’t form easily so reactivity decreases. Harder to gain the last electron,
