Across
- 2. a vertical column on the periodic table is called
- 5. elements with similar properties are located in the same column. Therefore, the properties of the elements on the periodic table repeat at regular intervals. This principle is known as the
Down
- 1. who was the first person to use the periodic table to make predections
- 3. a horizontal row on the periodic table is called
- 4. in 1860 how many elements were known by scientists