Early Periodic Table

Early Periodic Table

Where did we start

Early Days

The earliest attempt to classify the elements was in 1789 when Antoine Lavoisier grouped the elements based on their properties into gases, non-metals, metals, and earths. Several other attempts were made to group elements together over the coming decades.

Early Days

 In 1829, Johann Döbereiner recognized triads of elements with chemically similar properties, such as lithium, sodium, and potassium, and showed that the properties of the middle element could be predicted from the properties of the other two.

It was not until a more accurate list of the atomic mass of the elements became available at a conference in Karlsruhe, Germany in 1860 that real progress was made towards the discovery of the modern periodic table.

Alexandre Béguyer de Chancourtois

The telluric screw plotted the atomic weights of the elements on the outside of a cylinder so that one complete turn corresponded to an atomic weight increase of 16.

John Newlands

Just four years before Mendeleev announced his periodic table, Newlands noticed that there were similarities between elements with atomic weights that differed by seven. He called this The Law of Octaves, drawing a comparison with the octaves of music. He is the first to notice what we now call the Periodic Law.

Julius Lothar Meyer

His 1868 table listed 28 of the elements in order of atomic weight, with elements with the same valency arranged in vertical lines, strikingly similar to Mendeleev’s table. Unfortunately for him, his work was not published before Mendeleev. Give credit for the first periodic table to Mendeleev.

Dmitri Mendeleev

Was one of the first to arrange the elements by both atomic masses but also arranged them into vertical groups of matching properties. He was so confident in his table he left empty slots for undiscovered elements that should fit between known elements. His predictions were proven correct.

Dmitri Mendeleev

This new arrangement and creation of a periodic table allow for the properties of elements to be predicted even if they were previously undiscovered.

Dmitri Mendeleev

This new arrangement and creation of a periodic table allow for the properties of elements to be predicted even if they were previously undiscovered.

Multiple Choice

Dmitri Mendeleev

• formulated the first Periodic Law and created a farsighted version of the periodic table of elements that arranged elements by their properties and not atomic mass.

• He formulated the periodic table based on atomic numbers better fitting the periodic law and pattern seen by scientists.

• a vertical column of elements in the periodic table; elements in the same group share chemical properties

• a region of an electron subshell where there is a high probability of finding electrons.

Multiple Choice

The periodic table

• permits the properties of an element to be predicted before the element is discovered.

• will be completed with element 119.

• has been of little use to chemists since the early 1900s.

• was completed with the discovery of the noble gases.

Multiple Choice

Mendeleev predicted that the spaces in his periodic table represented

• isotopes.

• radioactive elements.

• unstable elements.

• undiscovered elements.

Multiple Choice

Mendeleev noticed that properties of elements usually repeated at regular intervals when the elements were arranged in order of increasing

• atomic number.

• density.

• reactivity.

• atomic mass.

Multiple Choice

Mendeleev left spaces in his periodic table and predicted the existence of three elements and their

• atomic numbers.

• colors.

• properties.

• radioactivity.

Multiple Choice

The idea of arranging the elements in the periodic table according to their chemical and physical properties is attributed to

• Mendeleev.

• Moseley.

• Bohr.

• Ramsay.