Periodicity And Ionisation Energy Flashcards
what do all elements in a group have
similar chemical properties
how is the periodic table organised
the periodic table is organised by increasing Atomic Number
what 3 physical properties can we study
we can study - covalent radius
- electronegativity
- ionisation energy
what does covalent radius measure
covalent radius measures the size of an atom
on a periodic table moving left to right what happens to the covalent radius
the covalent radius Decreases moving left to right in a periodic table
why does the covalent radius of an atom decreases moving left to right in a covalent molecule
it decreases due to the Nuclear Charge ( number of positive protons in the nucleus ) increases.
what happens to the covalent radius when you move down a group
the covalent radius increases as there is an extra energy level added
what is ionisation energy
Ionisation energy is the energy change when removing “1 mole of electrons from 1 mole of atoms in the gas state”.
what is the equation for ionisation energy
X(g) –> X^+(g) + e^-
X can represent any element
when moving down a group in the periodic table what happens to the covalent radius
the covalent radius increases when you move down a group in the periodic table
when laying out the formula for ionisation energy what is needed to represent the state of the element
X(g) –> X^+(g) + e^-
the (g) represents that the element is in the gaseous state
across a period what happens to ionisation energy
ionisation energy increases as: the covalent radius decreases (outer electrons are moving closer to the charge)
the nuclear charge increases (greater attraction between the nucleus and the electrons)
going down a period what happens to ionisation energy
ionisation energy decreases as the radius increases as more energy levels are added (the outer electron is farther from the nucleus)
define shielding
shielding is when the inner energy levels prevent the outer electrons from feeling the attraction of the nucleus.
explain why the second ionisation of sodium takes so much energy
the second ionisation of heat energy takes so much energy as you have to break into a full, stable shell.
Sodium’s first ionisation goes 2)8)1 to 2)8
Sodium’s second ionisation goes 2)8 to 2)7
upon breaking this stable shell it takes far more energy
