Development of the periodic table

Question 1

List the significant models for ordering the elements.

Answer 1

Dobereiner: Triads (based on atomic mass).

Newlands: Octaves (every eighth element has similar properties).

Mendeleev: Periodic law based on atomic mass.

Moseley: Periodic law based on atomic number.

Modern Periodic Table: Organised by atomic number, group behavior.

Question 2

State how the elements are ordered in the periodic table.

Answer 2

Organised by their atomic number and group behavior.

Question 3

Describe how the elements are arranged in groups and periods in the periodic table.

Answer 3

Elements in the same group, have the same number of electrons in the outer shell.

Elements in the same period have the same number of shells in the atom.

Question 4

Explain why the periodic table was a breakthrough in how to order elements.`

Answer 4

The periodic table was a breakthrough because it organized elements logically according to their atomic number and properties, revealing underlying patterns and trends. It allowed for predicting new elements, clarified relationships between known elements, and became an essential tool for understanding chemistry, revolutionizing the study of the elements.

Question 5

Are Noble gases reactive/ unreactive?

Answer 5

They are unreactive.