Trends In The Periodic Table Flashcards
Does electronegativity increase or decrease across a period? Why?
Increases. Atoms have greater nuclear charge and a smaller radius, easier to attract an electron than to lose one.
Does electronegativity increase or decrease down a group? Why?
Decreases. Atomic number is increasing, greater atomic radius, easier to lose an electron than to gain one.
Define ionisation energy.
The amount of energy required to remove one mole of electrons from one mole of an element in its gaseous state.
Does ionisation energy increase or decrease across a period? Why?
Increases. Harder to lose an electron due to nuclear charge increasing.
Does ionisation energy increase or decrease down a group? Why?
Decreases. Due to extra shielding, less attraction from the nucleus.
Define electron affinity.
Ability of an atom to accept an electron.
Does electron affinity increase or decrease across a period? Why?
Increases. Caused by decrease in atomic radius.
Does electron affinity increase or decrease down a group? Why?
Decreases. Caused by increase in atomic radius.
Define atomic radius.
One half the distance between the nuclei of two atoms.
Does atomic radius increase or decrease across a period? Why?
Decreases. Nucleus attracts electrons more strongly due to increasing atomic number.
Does the atomic radius increase or decrease down a group? Why?
Increases. Electrons occupy higher levels, atomic number doesn’t increase as much. Less attraction between the nucleus and outer electrons.
Do metals usually have a high or low melting point?
High.
Do non-metals usually have a high or low melting point?
Low.
What element has the highest melting point?
Carbon.
Define metallic character.
The ability to lose electrons.
