How was John newlands periodic table arranged
It was arranged in increasing atomic weight and every 8 elements had similar characteristics.
it was no taken seriously as similar elements had similar atomic weight and different property’s.
How did demitri mendeleevs periodic table change
He switched out elements that had similar properties and left gaps for elements that had not been founded yet.
What periodic table was accepted
Demitri mendeleevs
As he left gaps for elements yet to be found and he predicted there properties and he was right
How is the modern arranged
It’s arranged in proton number and atomic weight
Nobel gases were added
What are the properties of group 7-Halogens (4)
- All form covalent bonds
- melting/boiling points increases down the group
- form covalent compounds with other non-metals
- elements down a group can’t gain electrons as easily and there’s a greater distance between the nucleus and outer shell electrons
What’s an example for displacement reaction between sodium + Florine Bromide
Florine is more reactive and is higher in the group and bromine is less reactive and lower in the group
So it becomes: sodium + bromine fluoride
What’s the properties of group 1-alkaline metals (3)
- 1 electron on its outer shell
- all are soft
- reactivity increases down the group
What’s the properties of group 0-Nobel gases (4)
- they have a stable arrangement (8 electrons on its outer shell)
- monatomic (single-atom gases)
- no tendency to react
- boiling points increase as you go down the group
Why does the reactivity of group 1 metals increase down the group
As they are larger atoms, so the outermost electrons are fitter from the nucleus. Meaning the weaker electrostatic force of attraction and more shielding between the nucleus and outer shell electrons. It’s easier to loose electrons.
