Groups In The Periodic Table Flashcards
What are group 7 elements known as?
Alkali metals
Why do the alkali metals have similar chemical properties?
They all have one outer electron
What are the physical properties of group 1 elements?
Low melting and boiling points
Soft
What do alkali metals form?
Ionic compounds
They lose their single outer electron so easily they cannot share it- they don’t form covalent bonds
Why are group 1 elements very reactive?
They readily lose their single outer electron to form a 1+ ion with a stable electronic structure
What happens to the reactivity going down group 1?
It increases
Why does reactivity increase going down group 1?
The outer electron is easily lost as its further from the nucleus (larger atomic radius) so its less strongly attracted to the nucleus and less energy is needed to remove it
What happens when group 1 elements are put in water?
They react vigorously
Hydrogen gas and a hydroxide of the metal are produced
What are group 7 elements known as?
Halogens
Why do group 7 elements have similar chemical properties?
They all have 7 electrons in their outer shell
What do the halogens exist as?
Diatomic molecules (eg Cl2)
How do the halogens gain a full outer shell?
They share a pair of electrons in a covalent bond
What physical properties do the halogens have?
The melting and boiling points increase Colour gets darker At room temperature: Chlorine= green gas Bromine= red brown liquid Iodine= grey crystalline solid
How is chlorine tested for?
Using damp blue litmus paper
Chlorine will bleach the paper and turn it white
It may turn red for a second because chlorine is acidic
What happens to reactivity going down group 7?
It decreases