The Periodic Table and Writing Chemical Formulas (Junior Cert Science): Flashcards

Chemical elements showing repeating patterns

Number of protons in the nucleus

Vertical columns; same group = similar properties

Number of electron shells an atom has

Number of electrons in outer shell

Charged atom or group of atoms

Cation = positive (lose e⁻); Anion = negative (gain e⁻)

Force of attraction between oppositely charged ions

Force of attraction when atoms share electron pairs

1 H atom combines (e.g., HCl, HF)