The electron configuration for an element is 1s22s22p63s1 What is the atomic number of the element?

Asample of radium-226 will decay 1/4 of its original amount after 3200years. what is the half-life of radium-226?

Which of the following signs of a chemical reaction are observed in the reaction of potassium with water? precipitate formed temperature change smell produced gas produced color change

Achemist wants to extract copper metal from copper chloride solution. the chemist places 0.50 grams of aluminum foil in a solution containing 0.75 grams of copper (ii) chloride. a single replacement reaction takes place. (ii) chloride. a single replacement reaction takes place. which statement explains the maximum amount of copper that the chemist can extract using this reaction? a) approximately 0.36 grams, because copper (ii) chloride acts as a limiting reactant b) approximately 1.8 grams, because copper (ii) chloride acts as a limiting reactant c) approximately 0.36 grams, because aluminum acts as a limiting reactant d) approximately 1.8 grams, because aluminum acts as a limiting reactant