Groups in The Periodic Table Flashcards
What are groups, what do they show about each atom and what does it mean?
- Columns in the periodic table
- shows that each atom in this column has the same number of electrons in its outer shell
- Means that they have the similar chemical properties
What are the properties of alkali metals?
- soft
- low melting point
How do lithium, sodium and potassium react with water?
- Lithium: Bubbles fiercely and fizzes steadily
- Sodium: Melts into a ball
- Potassium: Bursts into flames and moves quickly around the surface of the water
What do alkali metals reactions with water show about alkali metal’s reactivity?
- Gets more reactive the further down the group you go
Explain the reactivity of alkalis in terms of electron configuration
- As you go down group 1, the number of electron shells in the atom increases. This means that the distance between the positively charged nucleus and the outer electron increases, so the forces of attraction weaken and the outer electron is easier to lose
What are the colours of chlorine, bromine and iodine at room temperature?
- Chlorine is yellow-green gas
- Bromine is a red brown liquid
- Iodine is a grey solid which gives off “purple vapour” when heated
- CHLORINE WATER IS COLOURLESS
- BROMINE WATER IS orange
IODINE WATER IS brown
Describe the pattern in physical properties of halogens? Why does this happen?
- The halogens change in state from gas to liquid to solid further down the group
- This happens because melting points increase as you go down the group.
- Gets darker further down you go in the group
What is the chemical test for chlorine?
When damp blue litmus paper is put into chlorine gas, it gets bleached
How do halides react with metals?
Form metal halides which are ionic compounds
How does reactivity change as you go down the group?
- as you go down the group, the elements get less reactive
- This is because there are more shells the further down you go, the more shells there are, the harder it is to react with an electron because of weaker attractive forces as the nucleus is further away from the electron it is trying to react with.
How do halogens react with hydrogen?
- Form soluble hydrogen halides
- React with water to form an acidic solution
How does chlorine react with bromine?
- Chlorine displaces bromine in a redox reaction.
Why are noble gases chemically inert?
They have a full outer shell
How do the properties of noble gases depend on
- Inertness
- Low density
- Non flammability
- Low density: Helium used in balloons and airships
- Non flammability: argon, krypton and xenon inside light bulbs so the filament doesn’t burn
- Inertness: Argon is used as a shield gas during welding
What is the pattern in physical properties in noble gases?
- Increases in density as you go down the periodic table
- Increases in boiling as you go down the group
