Periodic Law

Why the congress of 1860 in Karlsruhe was important for the chemical knowledge?

(Two options are correct)

• Dimitri Mendeleev presented the first periodic table in this congress, leaving invalid Canizzaro method.

• Italian chemist, Stanislao Canizzaro proposed a method to measure the relative mass on atoms.

• Chemist of all over the world agree that Uranium was a very radiactive element.

• The chemist agreed on atomic masses and initiated a search for a relationship with the chemical properties.

What was the Dimitri Mendeleev's contribution to chemistry knowledge?

• Discovered an organization based on Mercury and Silver, assigning the first atomic mass to these elements.

• Organized the first three periodic elements in horizontal form and with a random decision found nitroglycerin.

• The real contribution was made for Canizzaro that worked with Mendeleev to fins the 118 elements of the periodic table.

• Using the standardized method created cards with elements and their atomic masses. noticed frequent repetitions or periodic patterns.

What was the contribution of Moseley?

• Moseley noticed an undiscovered pattern, the element fit better when ordered in increasing form by their protons (nuclear charge).

• Moseley worked with Democritus to find the nucleus of the atom.

• Moseley noticed that the density of electrons organized better the properties of elements.

• Moseley worked to determine the number of protons and electrons of the 118 elements of the periodic table.

After all discussed, what is the periodic table?

• The periodic table describe the periods of the time that atoms where discovered and the properties of neutrons.

• The periodic tables organizes the elements by atomic mass, being the first element heavier and the last the lightest.

• The periodic table is an arrangement of the elements in

  order of their atomic numbers so that elements with similar properties fall in

  the same column, or group.

• The periodic table has seven rows and 15 columns where your organize elements by name.

What are the characteristics of Noble Gases?

• They are needed for life support in our planet.

  They are equivalent to oxygen and share the same reactivity.

• They are not reactive.

  They are in the group 18 of the periodic table.

  They are colorless and odorless.

  The outermost layer contains 8 electrons, therefore, they don't need any electron.

• They are the most reactive elements on the periodic table, due to need of electrons.

  They are in the 17 period of the periodic table.

• They are colorful and the smell is strongly acid.

  They form compounds with Nitrogen.

  All of them are in the sun transforming into Helium.

What are the main characteristics of lanthanides ?

(Two options are correct)

• They have almost the same physical properties.

  The process of identifying and separating them is tedious.

• They share the same properties that noble gases.

  They have the same arrangement than alkali group

• They are 14 element from 58 to 71.

  They have almost the same chemical properties.

• The nitrogen and oxygen are part of this group.

  They are also called halogens.

What are the properties of Actinides elements?

• They have the same characteristics than noble gases.

• They are 14 elements between 90 to 103.

  They belong to the group 7.

  They have radioactive elements like Uranium.

• They are part of Halogens.

  The alkali group does not react with this group.

  They are included in the periodic table arrangement.

• They were the first elements discovered.

  Their obtention is very simple and are abundant everywhere.

Explain the periodicity(pattern) in the periodic table.

• The propoerties follow a pattern that is a geometric sequence.

• In every group the difference of atomic numbers follows the rule 8, 8, 18, 18 and 32.

  Except by the Hydrogen.

• The properties follow a pattern and the rules is an arithmetic sequence.

• The properties follow a pattern that si the golden ratio.