The periodic table: s, p, d and f blocks
Write the electronic configuration of sixteen elements, from hydrogen and sodium to iron and uranium, find their group and period, and sort them into the s, p, d and f blocks.
Core concept
The modern periodic law says the properties of elements are a periodic function of their atomic numbers; elements are placed by electronic configuration, and the subshell that gets the last electron decides the block: s, p, d or f
Topic: Classification of elements
In 1869 Dmitri Mendeleev arranged the elements known then by atomic mass: How much matter something has, measured in grams or kilograms. It is the same everywhere. All key words and noticed that similar properties repeated: his periodic law. He left gaps for elements not yet discovered and predicted their properties. Later, Henry Moseley showed that atomic number is more basic, giving the modern periodic law: the properties of elements are a periodic function of their atomic numbers. In the modern periodic table, rows are periods (the number of shells) and columns are groups. Electrons fill shells, and within them subshells (s, p, d, f). The block is named after the subshell that receives the last electron: groups 1 and 2 are the s-block, groups 13 to 18 the p-block, the transition metals in the middle the d-block, and the two rows at the bottom (lanthanides and actinides) the f-block.
What you will learn
- State Mendeleev's periodic law and the modern periodic law.
- Write the electronic configuration of the first 20 elements.
- Find the group and period of an element from its configuration.
- Classify elements into the s, p, d and f blocks.
Before you start
- Know that electrons are arranged in shells around the nucleus.
Materials
- A periodic table chart
Equipment
- Beads or bottle caps to model electron shells
Procedure
- Pick an element's card and look at its electronic configuration and position.
- Do this for at least eight elements.
- Sort every element into its block.