3.1.1 - Periodicity

Question 1

how are elements arranged in the periodic table?

Answer 1

• by increasing atomic (proton) number
• in periods showing repeating trends in physical and chemical properties (periodicity)
• in groups having similar chemical properties

Question 2

first ionisation energy

Answer 2

energy required to remove one mole of electrons from one mole of gaseous atoms for form one mole of gaseous 1+ ions

X(g) —> X+(g) + e-