Grade 8 · Atoms, Elements and the Periodic Table · The Periodic Table

Reading the Periodic Table

ChemistryCore25 min

Groups, periods and predicting properties from patterns.

Learning objectives

  • Locate elements using group and period.
  • Relate outer electrons to group number.
  • Predict properties of an element from its position.

NGSS alignment

  • HS-PS1-1

    Use the periodic table as a model to predict the relative properties of elements based on the patterns of electrons in the outermost energy level of atoms.

  • HS-PS1-2

    Construct and revise an explanation for the outcome of a simple chemical reaction based on the outermost electron states of atoms, trends in the periodic table, and knowledge of the patterns of chemical properties.

  • MS-PS1-1

    Develop models to describe the atomic composition of simple molecules and extended structures.

MYP criteria

  • Criterion AKnowing and Understanding

ENGAGE

A table that predicts the future

EXPLAIN

Groups, periods and patterns

Elements are arranged by increasing atomic number. Vertical groups share the same number of outer electrons, which is why they react in similar ways.

  • Group number (main groups) = number of outer electrons.
  • Period number = number of occupied electron shells.
  • Metals on the left, non-metals on the right, noble gases in group 18.

Interactive simulation · PhET

Build an Atom

Build the first 10 elements and compare their proton numbers with the periodic table.

While you explore

  1. What does the atomic number tell you?
  2. How does the outer shell relate to the group number?
Open full screen on PhET

Practice questions

0/1 correct

Level 1

Elements in the same group of the periodic table have the same...

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