Who came up with the idea that all the continent's were once joined together

Which type of substance ionizes partially and gives off hydrogen ions when dissolved in water? a. strong acid b. strong base c. weak acid d. weak base

Which statement can best be concluded from the ideal gas law?

Achemist 16 drop copper metal from copper chloride solution. the chemist place is 0.50 g of aluminum foil in a solution containing 0.75 g of copper (ii) chloride. a single replacement reaction takes place. which statement explains the maximum amount of copper that the chemist can extract using this reaction?