IGCSE Coordinated Science: Periodic Trends

University:
University of Cambridge
Course:
0455 IGCSE | Economics
Academic year:

2023
Views:

9

Pages:

2
Author:

anon

IGCSE Coordinated Science: Periodic Trends Describe the change from metallic to nonmetallic character across a period. ❖ Elements on the left, in Group 1, are all metallic. ❖ Elements in Group 2 are also metallic, but their metallic properties are less apparent than the elements in Group 1.E.g. They are less reactive. ❖ As you go across the group, elements slowly become less metallic, and elements in Group 4 become non-metals. However, they are still generally in the solid form. ❖ As you progress group 6,7,8 elements tend to be in the gaseous form. Describe the relationship between Group number, number of outer-shell (valency) electrons and metallic/non metallic character. ❖ The group number is closely related to the number of out-shell valency electrons. ➢ E.g. Sodium is in Group 1 and has 1 outer electron, chlorine is in Group 7 and has 7 outer electrons. ❖ In Group 7, as you go down the group, the substances progress from Gas to solid. e.g. Chlorine is a gas whilst iodine is a solid. ❖ In Group 1 and 2 and possibly 3, even as you down down the group, they are mostly metals, however melting points and boiling points tend to decrease for these substances