Periodicity Flashcards
(32 cards)
What is Periodicity?
Periodicity refers to the recurring trends that are seen in element properties.
What are some periodic properties?
- Atomic radius
- Ionic radius
- Ionisation energy
- Electron affinity
What is atomic radius?
Half the distance between the centres of two atoms that are touching.
What is the trend for atomic radius in the periodic table?
- Increases down a group
- Increases from right to left across periods
Why are electrons pulled closer to the nucleus?
The number of protons increases, so the positive charge of the nucleus increases. This means electrons are pulled closer to the nucleus, making the atomic radius smaller
What is ionic radius?
The distance between neighbouring ions in an ionic solid.
What is the trend for ionic radius in the periodic table?
- Increases down a group
- Increases from right to left across periods
Cations are ________ than their parent atoms.
Smaller
Anions are ________ than their parent atoms.
Larger
What is ionisation energy?
the energy needed to remove an electron from an ion or gaseous atom
What is the trend for ionisation energies in the periodic table?
- Increases going up a group
- Increases from left to right across periods
The _______ ionisation energy is always greater than its first ionisation energy.
Second
The _______ ionisation energy is always greater than its second ionisation energy.
Third
What is electron affinity?
The amount of energy released when an electron is added to a gas-phase atom
What is the trend for electron affinity in the periodic table?
- Increases going up a group
- Increases left to right across periods
What are the elements with the highest electron affinities?
- Oxygen
- Fluorine
- Chlorine
What are the elements in the s-block?
Reactive metals
In terms of electrons, explain the property of elements in the p-block
They tend to gain electrons to complete closed shells
Diagonally related pairs of elements show what?
Similar chemical properties
Which two other blocks do d-block metals have similar properties to?
s-block and p-block
Which elements (in terms of blocks) form cations?
Many d-block elements
Noble gases are _______.
Inert (do not move, or react chemically with other substances)
Who published the first version of the periodic table of elements?
Dmitri Mendeleev
What are group 1 elements?
Alkali metals
