Module 3: Periodic Table And Energy Flashcards
What is the periodic table arranged by?
Increasing atomic numbers.
What does a ‘Group’ on the periodic table represent?
Colums, the number of electrons in the outer shell of an element.
What does a ‘Period’ on the periodic table represent
Rows, number of electron shells
As you move across a period what is the trend in Atomic Radius and why?
Atomic radius decreases, as the number of protons increase so does the positive charge in the nucleus, further attracting the electrons inwards.
What is ‘Ionisation Energy?’
The energy needed to form positive ions.
What is ‘first ionisation energy?’
The energy required to remove one electron from each atom in one mole of gaseous atoms to form one mole of gaseous 1+ ions.
Example of First Ionisation Energy Equation:
Give the equation for the first ionisation of Hydrogen.
H(g) -> H+(g) + e-
What is the ‘Second Ionisation Energy?’
The energy required to remove one electron from each ion within one mole gaseous, +1 ions to make one mole of gaseous +2 ions.
Example of Second Ionisation Energy Equation:
Give the equation for the second ionisation of Helium.
He+1 (g) —> He+2 (g) + e-
What are the three factors effecting Ionisation Energy and why do these have an effect?
- Atomic Radius: The larger the distance between the nucleus and the outer electron, the less attraction there will be.
- Electron Shielding/Repulsion: Inner shells of electrons repel outer shell electrons as they are all negatively charged, reducing the attraction.
- Nuclear Charge: The higher the nuclear charge, the larger the attractive force on outer electrons.
How can you figure of what element is being represented in a ‘Successive ionisation energies’ graph?
Between shells of electrons, there will be a large increase in ionisation energies; providing evidence for the number shells and the number of electrons in each shell.
What is the Trend in Ionisation Energy across a period and why?
Ionisation Energy increases across a period as the nuclear charge increases, shielding stays the same and atomic radius decreases.
What is the trend in Ionisation Energy down a group and why?
Ionisation Energy decreases, as the atomic radius increases, more electron shielding and nuclear charge decreases.
What is ‘Metallic Bonding?’
The electrostatic attraction between Metal cations and delocalised electrons.
What is a ‘Cation?’
A positive ion
(Cat-ions are paw-sitive… no? okay.)
What is an Anion?
A negatively charged ion.
Describe the structure in a Giant Metallic Lattice.
A pool of delocalised electrons in a giant lattice of regularly arranged positive ions.
What are the properties of Giant Metallic Lattices? (hints: m.p. b.p., e, m, d)
- High melting and boiling points: Strong electrostatic attraction requires lots of energy to overcome.
- Conducts electricity: as electrons can freely move around, carrying electrical charges.
- Ductile (can be stretched) and Malleable (shaped): as ions can slide over each other.
