Periodicity Flashcards
How is the periodic table organized?
The periodic table is arranged into periods and groups by atomic number.
What is the same in elements in the same period?
Elements in the same period have the same number of electron shells.
What is the same in elements in the same group?
Elements in the same group have the same number of electrons in their outer shell- so they have similar properties.
What is the trend of atomic radius across a period?
As the number of protons increases, the positive charge of the nucleus increases. This means electrons are pulled closer to the nucleus, making the atomic radius smaller.
The extra electrons that the elements gain across a period are added to the outer energy level so they don’t provide any extra shielding effects.
What is the trend of melting point across a period and why?
Melting points vary across a period as they depend on the structure of elements and the bonding within them. e.g metallic or covalent etc.
What is the trend of ionization energy across a period?
Ionization energy generally increases across a period. This is because of the increasing attraction between the outer shell electrons and the nucleus, due to the number of protons increasing.
