Chemistry Chapter 6 Review

Dmitri Mendeleev

Agreed with Newland that properties repeated, however he believed periods were not fixed in length. Placed 7 elements in the first two periods and then 17 in the third arranged in order of increasing atomic mass. Left blank spots to account for elements that had not yet been discovered. He knew that elements belonged there and even predicted their properties.

How does electronegativity vary within groups and across the periods

Decrease from top to bottom Increase from left to right

What happens to ionization energy within groups and across periods

Decreases from top to bottom increases across period

Henry Mosely

Determined that the periodic properties lined up better if elements were arranged by increasing atomic number, not atomic mass. This solved Mendeleev's problems. He also stated the Periodic Law.

How does atomic size change within groups and across periods.

General increase in size moving down groups General decrease moving across periods

What property did Mendeleev use to organize his periodic table?

He organized his table into periods with like properties and put it in increasing order by atomic mass.

John Newlands

Law of Octaves, Noticed properties repeated every 8 elements, arranged 49 known elements into rows of 7 arranged in order of increasing atomic mass

Johan Dobereiner

Law of Triads, Grouped Elements into triads, mass of 2nd element is midway between the 1st and 3rd

What was the major difference between the periodic table Newlands created and the periodic table Mendeleev created?

Mendeleev believed that periods were not fixed in length, and Mendeleev also accounted for elements that weren't even known yet.

Why did Mendeleev leave spaces in his periodic table?

Mendeleev left blank spaces in his periodic table because he organized the elements by their properties and left spaces to ensure the elements stay in groups of like properties. He knew that their were elements that belonged in the blank spaces, they were just undiscovered at the time. He was even able to predict the properties of the missing elements.

How did Mosely arrange the elements on the periodic table?

Mosely arranged the elements by increasing atomic mass.

How do ions form?

Positive and negative ions form when electrons are transferred between atoms

Why do the elements potassium and sodium have similar chemical properties.

Potassium and Sodium have similar chemical properties because they are in the same group on the Periodic Table.

Properties of metals

Shiny luster, high malleability, ductility, electrical and thermal conductivity.

Compare the size of ions to the size of the atoms from which they form

The size of ions are either larger or smaller -Cations are smaller -Anions are Larger

properties of nonmetals

dull, brittle, poor conductors of electricity and heat

State the periodic law

the physical and chemical properties of the elements are periodic functions of their atomic numbers