3.1.1 Describe the arrangement of elements in the periodic table in order of increasing atomic number
- in the periodic table, elements are placed in order of increasing atomic number from left to right, down the table
3.1.2 Distinguish between the terms group and period
- elements with the same number of valences electrons are placed vertically in the same column, called a group (or family)
- Group 1: alkali metals. Group 7: halogens. Group 8: noble gases.
- elements with the same number of main energy levels/shells are placed horizontally in the same row, called a period
3.1.3 Apply the relationship between the electron arrangement of elements and their position in the periodic table up to Z=20
- the sum of the numbers in the electron arrangement (for a neutral atom) will be the atomic number of the element and indicate their position in the table
3.1.4 Apply the relationship between the number of electrons in the highest occupied energy level for an element and its position in the periodic table
- the electrons in the highest occupied energy level are the valence electrons
- the number of valence electrons corresponds to the group # and indicates which group/family the element is in