23. Examine the graph below, and answer the following questions: a. What is the boiling point of the sub- stance? What is the melting point? b. Which state is present at 30°C? c. How will the substance change if energy is added to the liquid at 20°C? 80 60 Temperature (°C) 40 20 0 Energy

answer: atomic mass was originally used to arrange elements on the periodic table, but is no longer used to organize the modern version.

explanation:

originally atomic mass was used to arrange elements on the periodic table from left to right in a row. each column then shows similar properties of elements of a group.

in modern periodic table, the atoms are arranged in increasing atomic number. as atomic number represents the number of protons in an atom which is unique for every atom.