C3.1.3 Trends within the periodic table Flashcards
What are group 1 elements called?
Alkali metals.
Give 4 properties of alkali metals.
Highly reactive with water
Soft + can be cut easily with a knife
Low densities
Form hydroxides that dissolve in water to give alkaline solutions
What is the general equation for an alkali metal reaction with water?
group 1 metal + water → group 1 metal hydroxide + hydrogen
What happens to the properties of alkali metals when you go down the group?
The melting points and boiling points decrease.
The reactivity increases.
What do alkali metals form when they react with non metals?
Ionic compounds - white solids which form colourless solutions when they dissolve.
Describe what happens when an alkali metal reacts with a non metal.
The alkali metal loses an electron, becoming a positively charged ion.
What are the properties of transition metals compared to alkali metals?
Higher melting points (except for mercury)
Higher densities
Stronger and harder
Less reactive
What do transition metals form when they react?
Coloured compunds
Give a common use of transition metals.
Catalysts
What are group 7 elements called?
Halogens
Describe what happens when a halogen reacts with a metal.
It forms ionic compounds in which the halide ion carries a charge of –1.
What happens to the properties of halogens when you go down the group?
The melting point and boiling point increase
The reactivity decreases
What happens in a halogen displacement reaction?
A more reactive halogen can displace a less reactive halogen from an aqueous solution of its salt.
What does the reactivity of an element depend on?
How easily its atoms lose or gain electrons.
What happens to metals when they react with non metals?
Metal atoms lose electrons when they react with non-metals.
