1. (chemistry) the principle that chemical properties of the elements are periodic functions of their atomic numbers
   - Mendeleev's law

Derived forms: periodic laws

Type of: law, law of nature

Encyclopedia: Periodic law

• hard-bitten
• hard-boiled
• hard-boiled egg
• hard-cooked egg
• hard-fought
• hard-hitting
• hard-nosed
• hard-of-hearing
• hard-on
• hard-pressed
• hard-shell
• hard-shell clam
• hard-shell crab
• hard-shelled
• hard-skinned puffball
• hard-to-please
• hard-wearing
• hard-won
• hardback
• hardbacked
• hardbake
• hardball
• hardboard
• hardbound
• hardcore