In 1869, Dmitri Mendeleev developed a periodic table of the known elements by observing patterns of regular behaviors in the properties of the then known elements. After making observations, he placed the elements in rows such that similar properties fell into columns. Finally, Mendeleev was able to use this table to predict the properties of undiscovered elements. Years later, Moseley readjusted Mendeleev's effort to form the Modern Periodic Table and Modern Periodic Law that states:

**Arranging the elements by increasing atomic number in the shape of the Periodic Table will provide periodic trends (or in other word, fixed patterns) of known properties of elements.**

Here, you are going to simulate Mendeleev's/Moseley's efforts. You are given 23 of the 24 pieces of a puzzle. Each piece has six properties (characteristics, i.e. stars). Your goal is to develop a "periodic table" (or arrange the pieces) such that there is a pattern to each property. **Hint, It is a square/rectangular puzzle.** Finally, from the patterns discovered, you will be able to describe all the properties of the missing piece.

1.__________________________________ 4. ________________________________

2.__________________________________ 5. ________________________________

3.__________________________________ 6. ________________________________

1.

2.

3.

4.

5.

6.