Chemistry - Atoms, Bonds and Groups - F321 - The Periodic Table (3) Flashcards
Who introduced the letter based symbols for elements?
Jons Jakob Berzelius introduced the letter based symbols for elements.
Who proposed the ‘law of triads’?
Johann Wolfgang Dobereiner proposed the ‘law of triads’.
In what year did Johann Wolfgang Dobereiner propose the ‘law of triads’?
In 1829 Johann Wolfgang Dobereiner proposed the ‘law of triads’.
What is the ‘law of triads’?
The ‘law of triads’ states that the middle element of three elements has properties that are an average of the other two members of the triad when ordered by atomic weight.
Who developed an early form of the periodic table arranged in a cylinder in increasing atomic weight and similar properties aligned vertically?
Alexandre Emile Béguyer de Chancourtois developed an early form of the periodic table arranged in a spiral on a cylinder in increasing atomic weight and similar properties aligned vertically.
Who was the first person to devise a periodic table arranged in order of atomic weight?
John Newlands was the first person to devise a periodic table arranged in order of atomic weight.
What was John Newlands the first person to do?
John Newlands was the first person to devise a periodic table arranged in order of atomic weight.
In what year was Mendeleev’s periodic table published?
Mendeleev’s periodic table was published in 1869.
Who published a periodic table about a year after Mendeleev, unaware of his work?
Julius Lothar Meyer independently published his own periodic table about a year after Mendeleev, unaware of his work.
Who determined the atomic number for each of the elements?
Henry Moseley determined the atomic number for each of the elements.
What elements are the semi-metals or metalloids?
Boron, silicon, germanium, arsenic and tellurium are the semi-metals or metalloids.
Define periodicity.
Periodicity is a regular periodic variation of properties of elements with atomic number and position in the periodic table.
What elements will have the same number of electrons in their outer shell?
Elements in the same group will have the same number of electrons in their outer shell.
In general ionisation energies …….. across each period.
In general ionisation energies increase across each period.
Down a group, the first ionisation energies ……….
Down a group, the first ionisation energies decrease.
From group one to group four there is a general ………. in boiling points.
From group one to group four there is a general increase in boiling points.
From group four to five there is a ……….. in boiling point.
From group four to five there is a sharp decrease in boiling point.
From group five to zero ……… boiling points.
From group five to zero they have comparatively low boiling points.
Group 2 elements are the ………
Group 2 elements are the alkaline earth metals.
Group 2 elements have reasonably ……. melting and boiling points.
Group 2 elements have relatively high melting and boiling points.
