Chapter 4: Periodic Table Flashcards
Ancient Greeks thought that all matter in the universe was made of only how many elements?
5
Do the symbols of each element always use just two letters?
No
Who recognized groups of three elements with similar properties?
Johann Doberiener
How did the ideas of triads influence the development of the periodic table, even though more than three elements share similar properties?
-Established element families
-Established element groups numbered 1-18
-Gave rise to the idea of octaves.
Who observed that when the elements were arranged by increasing atomic mass, every eighth element often had similar properties?
John Newlands
What was the unique feature of Mendeleev’s classification method?
The blank spaces that he left between elements.
Do the properties of elements vary in a periodic way?
Yes
Which scientist’s discoveries led to organization the periodic table using atomic numbers rather than atomic mass?
Henry Mosely
What is the modern periodic table arranged by?
Atomic number
Elements in the same ________ on the periodic table have the same number of valence electrons.
Column
How many periods does the modern periodic table have?
7
How many groups does the modern periodic table have?
18
Is a family the same as a period on a periodic table?
No
The first two elements of the periodic table, hydrogen and helium, are in the same what?
Period
How would a highly conductive, malleable, and lustrous solid most likely be classified?
Metal
What are the general properties of metals?
Dense, lusterous, highly conductive, reactive, malleable, ductile, have few valence electrons
What group is highly conductive and reactive?
Metals
What group are ductile, malleable, and lusterous?
Metals
What group includes almost 80% of the elements?
Metals
Where are metalloids found on the periodic table?
Along the stair step line
What group exists naturally as a gas, liquid, or a dull solid?
Nonmetals
Which group are semiconductors?
Metalloids
Which group possesses four to eight valence electrons?
Nonmetals
Where are nonmetals found on the periodic table?
To the right, but not touching the stair step line.
Which group are brittle solids with metallic luster a part of?
Metalloids
What group would alkali metals be located in?
1
How many valence electrons do the alkaline-earth metals have?
2
What elements make up Group 2?
Alkaline-earth metals
What type of group are alkaline metals in?
Group 1
How many valence electrons do alkali metals have?
1
What elements make up groups 3-12?
Transition metals
Why are halogens an unreactive family?
They have eight valence electrons.
How many valence electrons do noble gases have?
2 or 8
What elements make up groups 13-16?
Mixed groups
How many valence electrons does every element in halogen have?
7
What is included in an element’s electron dot notation?
Element’s chemical symbol number of its valence electrons.
Does the atomic radius generally decreases from top to bottom down a column on the periodic table?
No
Are atomic radius and electronegativity closely related?
Yes
Are alkali metals very reactive?
Yes
How many valence electrons do most transition metals have?
1 or 2
What type of ions do alkaline-earth metals form?
2+ Cation
How many valence electrons do most transition elements have?
1 or 2
How many valence electrons does silicon have?
4
What affects the size of an element’s atomic radius?
The number of energy levels and additional protons.
Does electronegativity generally decrease from top to bottom down a column on the period table?
Yes
