Jorge is studying the history of the periodic table. Since 1869, the periodic table has been revised as new elements have been identified. In the modern periodic table, which of the following describes atoms with similar chemical behavior and properties? They have similar atomic masses They are located within the same group They are located within the same period They have the same number of isotopes

The characteristics of two different types of reactions are shown below: reaction a: electrons are gained by the atoms of an element. reaction b: protons are lost by the atom of an element. which statement is true about the atoms of the elements that participate in the two reactions? their identity changes in both reaction a and reaction b. their identity changes in reaction a but not in reaction b. their identity changes in reaction b but not in reaction a. their identity remains the same in both reaction a and reaction b.