Periodocity Flashcards
What is red stepped line
Divides metals from non metals those touching have a combo of metal and non metal
What is a group
Vertical line on periodic table elements have same number of electrons in the outer shell
What happened to metal reactivity going down
Get more reactive going down
What happens to non metals going down a group
They get less reactive
What are periods
Horizontally row on periodic table contains same electron shell number
Why isn’t helium part of the p block
Electron is on the s block
What does silicon form
Covalent bonds as it has four electrons in outer shell so form covalent bonds
What do elements in group 567 form
Either covalent compounds or ionic compounds
What has greatest melting point in period 3
Silicon as it is a macromelucal or also known as giant covalent compound
What happens to the mp and no going across period 3
The metals have high belting point and the non metals have low melting point his is because of metallic bonding vs atomic bed bonding
Why does strength of metallic bonding increase going across period 3
From sodium to aluminium because the metals increase in nuclear charge so charge of ion increase so greater attraction between delocalised electron and the ion
Why does boiling point decrease going down non metals period 3
It’s dependent on the sizes of the code forces and it’s dependents on the number of electron in the molecule and how closely they can pack together
S8 p4 cl2
How to measure atomic radius
Half the distance between the centres of the pair of atoms
Why does atoms decrease across a period
You are adding more protons to he nucleus increase in the nuclear charge this pulls the electrons towards the nucleus as there is no additional electrons in shielding so atoms size decreases going across
Why does atomic radio increase going down a group
The atoms of each element has one more full electron shell sonincrease shielding and atomic radio increase
Also the electron is further from the nucleas
