Peridodic trends Flashcards
(32 cards)
Atomic Radius
Centre of the nucleus to the edge of the elctron cloud
Covalant Radius
Is the distance between the nuclei of 2 bonded atoms
Which periodic trend makes atoms smaller
Left to right across the period
becasue the ENC increases pulling the electron shells tighter
What effect does more protons have on the atom
increases attraction, makes atom smaller
What is Effective nuclear charge
The pull that stops electrons from flying away,
Increases closer to the nucleus
Who was the first to publish an organised periodic table
Dimitri Mendeleev was the first scientits.
What areas of the periodic table are call groups
The vertical
What area of the periodic table is called the period
The horizontal
Groups are atoms with?
Groups are atoms with the same amount of valance electrons
If atoms are in the same period it means they have the same?
Periods show how many electron shells there are
Properties of metals?
Metals are shiny, good conducutors of heat and electricity (Except Mercury)
Properties of non-metals
non-metals are dull, brittle, noncoonductors
Metaloids
Metaloids are shiny but brittle and are semi conductors
Where is the edge of a atoms electron cloud
Covalent radius, Half the distance between the nuclei of 2 bonded atoms
How are atomic radii measured
picometers or angstroms An angstrom is 1 x 10^-10
What is the atomic radius trend down the group
When do atoms get bigger
As you go down the group the atoms get larger.
Becasue u add a new shell each period down
What is the atomic radius trend across a period
Left-right it gets smaller becasue your adding more electrons and protons increasing the attractivness
Effective Nuclear Charge?
Is the pull an atom feels from the nucleus.
Charge increases the closer to the nuclaus
How is the effective nuclear charge effected by incresing protons
The ENC decreses as it gets further away from the nucleus, so the outer electrons are held less tightly
Ionisation Energy
The force required to pull an electron out of ENC
When the electron is given energy to release an eletron from the ENC.
the atom has been ionised
How is Ionisation energy measured
It is measured in Kilo Jouels (KJ)
How does ionisation energy change
The larger the atom is the less Ionisation energy is required to release an atom, becasue the ENC decreases as it gets further from the nucleus
Metallic Character
How easily atoms give up their electrons
Electronegativity
Atoms attraction for another atoms electrons
