What are group 1 metals known as
The alkali metals
What elements are in group 1
- lithium
- sodium
- potassium
- rubidium
- Caesium
- Francium
Why do alkali metals all have similar chemical properties
- They all have one electron in the outer shell
What are the physical properties of alkali metals
- Low melting and boiling points compared to other metals
- low density - Li, Na, K float on water
- Very soft - they can be cut with a knife
Why are group 1 metals reactive?
- They readily lose their one outer electron to form a +1 ion to get a stable electronic structure
- as you go down group 1 the alkali metals get more reactive
- because outer electron is easily lost because the atomic radius is larger
- therefore it’s less strongly attracted to nucleus and less energy needed to remove it
Describe the reaction between a alkali metal and cold water
- Reacts vigorously
- produces metal hydroxide + hydrogen
describe the reaction between rubidium and cesium with water
- react violently with watee and explode
what is the balanced equation of sodium + water
2Na+2H2O→2NaOH+H2
what is the base word equation for reaction of a group 1 metal with a dilute acid
- metal + acid → salt +hydrogen
sodium add hydrochloric acid
2Na+2HCl→2NaOH+H2
What are the group trends for group 1
Down the group:
- increasing atomic radius
- decreasing electronegativity
- increasing reactivity
- decreasing melting and boiling pointsincreasing atomic radius
What would you see when lithium reacts with water
- When lithium is added to wafter it floats.
- It fizzes steadily and becomes smaller, until it eventually disappears.
What is the word and symbol equation for lithium reacting with water
- lithium + water → lithium hydroxide + hydrogen
- 2Li(s) + 2H2O(l) → 2LiOH(aq) + H2(g)
What would you see if sodium reacted with water
- the sodium melts to form a ball that moves around on the surface
- It fizzes rapidly
- produces hydrogen that may burn with an orange flame before the sodium disappears.
What is the word and symbol equation of sodium reacting with water
- sodium + water → sodium hydroxide + hydrogen
- 2Na(s) + 2H2O(l) → 2NaOH(aq) + H2(g)
What would you see if potassium reacted with water
When potassium is added to water
- It melts and floats around very quickly on the surface of the water.
- The hydrogen ignites instantly.
- The metal is also set on fire, with sparks and a lilac flame.
- There is sometimes a small explosion at the end of the reaction.
What is the word and symbol equation for potassium reacting with water
- potassium + water → potassium hydroxide + hydrogen
- 2K(s) + 2H2O(l) → 2KOH(aq) + H2(g)
