Question

graphing periodic properties
the periodic table relies on patterns and similarities of the electron configuration and chemical properties of elements. the data table lists some melting points and boiling points of elements in groups 18, 17, 14, and 2. look where the elements in the table are located on the periodic table as you complete the activity, to help you understand their periodicity.
a graph of the atomic numbers versus melting point temperature.
sample answer:
melting points for 4 periodic groups

1. describe any relationships between atomic numbers and melting points.
2. using the melting point graph you constructed for group 14, estimate the melting point of an element with an atomic number of 25 (between ge and sn). show your reasoning using your graph.

Explanation:

Step1: Analyze the graph for relationship

By observing the graph of atomic numbers versus melting - points, we can see that there is no simple linear relationship. For different groups (Group 18, 17, 14, 2), the trends vary. In general, within a group, as the atomic number increases, the melting - point may show a certain trend. For example, in some groups, the melting - point may increase with an increase in atomic number, while in others, it may decrease or have a more complex pattern.

Step2: Estimate for Group 14

For Group 14, we first identify the positions of Ge (Germanium) and Sn (Tin) on the atomic number scale. Then, we look at the trend of the melting - point values for Group 14 elements on the graph. We assume a linear or a smooth non - linear interpolation between the known melting - points of adjacent elements in Group 14. If we assume a linear interpolation between the melting - points of Ge and Sn, we find the difference in atomic numbers and melting - points between them, and then calculate the estimated melting - point for an atomic number of 25. However, since the graph is not highly accurate for exact interpolation, we can only give a rough estimate. Let's say the melting - point of Ge is around 938°C and that of Sn is around 232°C. The atomic number of Ge is 32 and that of Sn is 50. The difference in atomic numbers $\Delta Z=50 - 32 = 18$, and the difference in melting - points $\Delta T=938 - 232=706$. The proportion of the distance from Ge to the element with atomic number 25 is $\frac{32 - 25}{18}=\frac{7}{18}$. The estimated melting - point $T$ is $T = 938-\frac{7}{18}\times706=938 - 273.6\approx664.4$°C.

Answer:

1. There is no simple linear relationship between atomic numbers and melting points. Trends vary among different groups. For some groups, melting - point may increase with atomic number, while for others, it may decrease or follow a more complex pattern.
2. Roughly 664.4°C (using linear interpolation between Ge and Sn in Group 14 based on the graph and atomic number differences).