The Periodic Table is an arrangement of all the known elements in order of increasing atomic number - Scottish Highers Chemistry - Question 5 - 2015

Group 1 elements, known as the alkali metals, are characterized by their soft texture, low density, and high reactivity, especially with water. As you move down the group (e.g., from lithium to cesium), reactivity increases, and melting points typically decrease, illustrating a clear periodic trend.

In contrast, Group 4 elements, which include carbon and silicon, display a diverse range of properties. For example, carbon exists in different allotropes, such as graphite and diamond, exhibiting varying hardness and electrical conductivity. Additionally, the elements in Group 4 show a trend of increasing metallic character as you move down the group, with elements such as tin and lead having different physical and chemical properties compared to carbon.

While both groups demonstrate patterns in reactivity and physical properties based on their placement in the periodic table, the fundamental nature and characteristics of the elements differ significantly between the two groups. This reflects how periodic trends not only govern reactivity and periodicity but also the underlying properties that define each group.