group 1 and group 7 (observations and reactivity trends ) Flashcards
What are the properties of group 1 metals?
- soft
- low density
- very reactive
- weak
- relatively low melting points (compared to other metals)
What are the group 1 elements called?
Alkali metals
State the 3 trends seen in group 1 metals as you go down the periodic table.
- Increased reactivity.
- Lower melting and boiling points.
- Higher atomic mass.
Why do alkali metals become more reactive down the group?
- As you go down the group, the atomic radius and shielding increases
- This means there is a weaker attraction between the outer electrons and the nucleus.
- This means that the amount of energy required to lose the outer-most electron decreases, which makes it easier to lose that outer electron
- Therefore reactivity becomes more reactive down group 1
What are the group 7 elements called?
Halogens
Are halogens metals or non-metals?
Non metals
State the three trends in the group 7 elements as you go down the periodic table.
- Decreased reactivity.
- Higher melting/boiling points.
- Higher atomic mass.
Down group 7, the atomic radius ___________ because there are more electron ___________.
Increases, shielding
The reactivity _________ down group 7.
Decreases
Halogen atoms have ___ electrons in the outer shell. They seek to achieve a ____ shell (8 electrons), this is because having a ______ outer shell ________ atoms.
7, full, full, stabilises
why does reactivity decrease as you go down group 7?
- the atomic radius and electron shielding increases
- meaning the attraction between the nucleus and the outer shell gets weaker.
- This makes it harder for the halogen to gain an outer electron.
what are the properties of group 1 metals that make them different from other metals
- soft
- low densities
-low melting points
-more reactive
