Alkali metals Flashcards
Give the name for Group 1
Alkali metals
How many electrons do all of the group 1 metals have in their outer energy level
All group 1 metals have 1 electron in their outer energy level
State the states of the group 1 metals at room temperature
All group 1 metals are solids at room temperature
What is the temperature of room temperature
Room temperature is approximately 25 degrees celcius
List some physical properties of the Group 1 metals
soft
low melting points
malleable
ductile
good conductors of heat
good conductors of electricity
low density
How many alkali metals are less dense than water and what does this mean
The first three alkali metals are less dense than water.
This means that the first three alkali metals can float on water
What is the trend in melting points in Group 1
Melting points decrease down the group as the metallic bonds between the atoms are weakened. This is because moving down the group, the atoms get larger, which means there is more shielding, which means the bonds between the atoms are weakened
What is the trend in boiling points in Group 1
Boiling points decrease down the group
What is the trend in reactivity in Group 1
Reactivity increases down the group
What is the trend in relative atomic mass in Group 1
The relative atomic mass increases down the group
Describe how lithium reacts with water
Effervescence
moves on the surface
Universal indicator has turned purple/colour of the indicator is darker near the lithium
The metal reduces in size and goes into the solution
Describe how sodium reacts with water
Effervescence
Sodium melts into a sphere
Sodium moves on the surface
Universal indicator has turned purple/colour of the indicator is darker near the lithium
The metal reduces in size and goes into the solution
Describe how sodium reacts with water
Effervescence
Potassium moves on the surface
Potassium ignites to give a lilac flame
Universal indicator has turned purple/colour of the indicator is darker near the lithium
The metal reduces in size and goes into the solution
Describe how caesium reacts with water
Caesium reacts explosively with water.
When Group 1 metals react, what happens to the Group 1 metal atoms in terms of electrons
Where do these electrons go
What type of compound is formed
Group 1 metals lose their outer electron to form 1+ ions
The electron was transferred to the substance it is reacting with
An ionic compound is formed.
Why are alkali metals called Alkali metals
Alkali metals are called Alkali metals because they react with water to form alkaline solutions
When an alkali metal reacts with water why is there fizzing
There is fizzing as hydrogen gas is being produced in the reaction
When an alkali metal reacts with water why does the metal move over the surface of the water
Alkali have a low density so they can sit on the surface of the water, it is the hydrogen gas that propels the metal
When an alkali metal reacts with water why does the universal indicator go purple
When an alkali metal reacts with water the universal indicator goes purple because an alkali is produced in the solution
When an potassium reacts with water why does it ignite to give a lilac flame
Potassium is more reactive and the heat ignites the hydrogen gas to give a characteristic lilac flame
When an alkali metal reacts with sodium why does sodium melt into a sphere
Sodium melts into a sphere as the heat generated from the reaction melts the sodium
When an alkali metal reacts with water why does the metal reduce in size and go into the solution
The metal reacts and goes into the solution as a soluble alkali is formed.
When alkali metals react with water what colour is the solution that is formed
When alkali metals react with water the solution produced is colourless.
The hydroxides of the alkali metals are all soluble in water
Describe what happens when the alkali metals are heated in chlorine gas
They react vigorously when heated in chlorine gas to form white metal chloride salts which are white solids
Can metal chlorides dissolve in water, if so what do they produce
Metal chlorides dissolve in water to form colourless solutions
When lithium is exposed to the air why does it tarnish
When fresh lithium is cut and exposed to air, it tarnishes because the lithium is reacting with the oxygen to form a layer of lithium oxide.
What do alkali metals produce when they burn in oxygen gas
When alkali metals burn in oxygen gas, they form white smoke of their oxides (the smoke is the compound)
Give an observation of when lithium burns in oxygen
Lithium burns with a red flame to produce a white solid
Give an observation of when sodium burns in oxygen
Sodium burns with a yellow-orange flame to give a white solid
Give an observation of when potassium burns in oxygen
Potassium burns with a purple flame to give a white solid
Explain the trend in reactivity of Group 1
Going down the group, the atoms become larger
The distance between the nucleus and the outer electron is greater, meaning it has more electron shells.
This results in increased shielding, which means the electrostatic attraction between the nucleus and the outer electron is weaker
Therefore, the outer electron is lost more easily.
Why is sodium more reactive than lithium
A sodium atom is larger than a lithium atom
This means that the distance between sodium’s nucleus and it’s outer electron is greater than the distance between lithium’s nucleus and outer electron, which means that sodium has more electron shells than lithium.
This results in more shielding being experienced by sodium than lithium , which means that the electrostatic attraction between sodium’s nucleus and outer electron is weaker than the attraction between lithium’s nucleus and outer electron,
Therefore, sodium’s outer electron is lost more easily
What do alkali metal produce when they react with water
When alkali metals react with water they form a metal hydroxide and hydogen
Complete the sentence:
Group 1 metals react with water forming an ______ solution and Hydrogen gas
Group 1 metals react with water forming an alkaline solution and Hydrogen gas
Define group
A group is a column in the periodic table where elements are arranged based on how many electrons are in their outer shell. The elements in a group share similar chemical properties
Define period
A period is a row on the periodic table where elements are arranged based on how many electron shell they have
