Group chemistry Flashcards
what are Group 0 known as ?
Noble Gases
State Group 0’s reactivity and explain why this is.
They are unreactive.
- They have a full outer shell of electrons
- No tendency to lose or gain electrons so it is inert.
State Group 0’s melting point trend as you go down the group and explain why this is.
The melting point increases down the group.
- This is because the atom size increases
- So there are more electron shells
- This means more intermolecular forces in the atom - Resulting in more energy to break these forces
State and Explain one use for Argon (Ar) and Helium (He)
Ar- Used in crisp packets
-it is unreactive
-this means it wont damage food
He- used in balloons
-it is non flammable and has a lower density than air
What are group 1 elements known as ?
Alkali metals
State and explain the trend in reactivity of the Alkali metals as you go down the group.
Reactivity increases
- Atom gets larger
- Nucleus and outer shell electron become further apart
- The electrostatic forces decrease
- Becomes easier for the atom to lose electrons.
sate and explain the trend of the melting point of the alkali metals as you go down the group.
melting point decreases.
- Atoms get larger
- Nucleus and delocalised electron are further apart
- Electrostatic forces decrease
-Requires less energy to overcome
when the first 3 Alkali metals react with water ( Li, Na and K) what happens ?
Li
- Fizzes
- Floats
Na
- Fizzes
- Floats
- Melts into a ball
K
- Fizzes
- Floats
- Melts into a ball
- Produces a lilac flame
Explain why the first 3 Alkali metals have the reactions that they do.
Li
- Floats because it is less dense than water
- Fizzes because it produces hydrogen gas
Na
- Floats because it is less dense than water
- Fizzes because it produces hydrogen gas
- Melts into a ball because it has high thermal energy and a low melting point
K
- Floats because it is less dense than water
- Fizzes because it produces hydrogen gas
- Melts into a ball because it has high thermal energy and a low melting point
- Produces a lilac flame because Hydrogen ignites
Do Alkali metals lose or gain electrons and state what ion this forms .
Lose 1 electrons.
- Forms a positive ion (1+)
What happens when the alkali metals react with chlorine ?
They all produce a white powder
What happens when the first 3 Alkali metals react with Oxygen ?
Li
- White powder
- Crimson flame
Na
- White powder
- Yellow flame
K
- White powder
- Lilac flame
What does each Halogen (non -metals) each exist as ?
Fluorine - very reactive yellow poisonous gas
Chlorine - poisonous dense green gas
Bromine - red - brown volatile liquid
Iodine - dark grey crystalline solid or a purple vapour
Explain the trend in the reactivity of Group 7 as you go down the group.
- Become less reactive
-outer shell becomes further away from the nucleus as the atom size increases - this makes it harder to gain another electron as the forces of atraction become weaker
State what happens as you go down the group to Group 7’s mpt and bpt.
-Increases
