Section 4 Flashcards
how do alkali metals react when they are put in water?
they all react vigorously (in a similar way)
what does the reaction between alkali metals and water produce?
a metal hydroxide solution (which is alkaline)
why are group 1 elements known as the alkali metals?
because they form an alkaline metal hydroxide solution
what does the reaction of alkali metals with water also produce?
hydrogen - this is why you can see fizzing
which elements in group 1 are most reactive?
group 1 elements become more reactive down the group as the atomic number increases
how can you tell that they become more reactive?
the rate of reaction with water increases
name 3 alkali metals.
Lithium (Li), Sodium (Na), Potassium (Ka), Rubidium (Rb), Caesium (Cs), Francium (Fr)
what are the properties of alkali metals?
- soft
- low density
- low melting point
what are the properties down the group of alkali metals?
- they are more reactive
- their boiling point decreases
why are alkali metals so reactive?
- they all have one electron in their outer shell
- further down the group the radium of the atoms get bigger
- the outer shell is further away from the positive nucleus
- positive nucleus holds outermost electron in place
- the distance weakens the attractive force
how are group 7 elements called?
halogens
as the atomic number of halogens increases…
- the less reactive
- the elements have a darker colour
- higher boiling point
which halogens are most reactive?
higher up group 7 elements are more reactive
whats the colour and physical state at room temperature of chlorine?
- green
- gas
whats the colour and physical state at room temperature of chlorine?
- colourless
- gas
