The Periodic Table Chapter 5
What is a nonmetal?
any element that is not a metal on the periodic table
What is a metalloid?
elements with properties that fall between those of metals and nonmetals.
What categories are used to classify elements on the periodic table?
metals, nonmetals, and metalloids
What is the most abundant element in the Earth's crust/
oxygen
How did Dmitri Mendeleev developed an approach for organizing the elements?
solitaire
What are the elements of Group 8A called?
Noble gases
What are the four pieces of information for each element?
atomic mass, atomic number, element symbol, element name
What name did Mendeleev give the missing element one space below Aluminum?
eka-aluminum
What is each column on the Periodic Table called?
group
How many valence electrons do group 2A have?
2
How many periods are there on the Periodic Table?
7
How do properties vary across a period in the periodic table?
Across a period from left to right, the elements become less metallic and more nonmetallic in their properties.
What are the characteristics of a nonmetal?
Brittle, poor conductors of heat and electricity, and low boiling points
What element is found in oyster shells and a plaster cast?
Calcium
What is unique about the elements in group 7A?
Despite their physical differences, the halogens have similar chemical properties
What element has the atomic number 82 and element symbol Pb?
Lead
What metal is a liquid at room temperature?
Mercury
What is the Element symbol for Molybdenum?
Mo
The element magnesium plays a key role in what biological process?
Photosynthesis
What element with the atomic mass of 39.098 is essential to muscle and nerve function?
Potassium
What element, atomic mass 50.941, plays a key role in the formation of teeth and bones?
Vanadium
What are the elements in Group 1A called?
alkali metals
What are the element in Group 2A called?
alkaline earth metals.
What is the most abundant metal in the Earth's crust?
aluminum
What is a periodic table?
an arrangement of elements in columns, based on a set of properties that repeat from row to row.
What is a valence electron?
an electron that is in the highest occupied energy level of an atom.
How did Mendeleev organize the elements in his periodic table?
arranged the elements into rows in order of increasing mass so that elements with similar properties were in the same column.
Why do the elements in a group have similar properties?
because they have the same number of valence electrons.
How is the modern periodic table organized?
by increasing atomic number (number of protons).
Besides water what element is in most of the compounds in the human body?
carbon
What evidence helped verify the usefulness of Mendeleev's table?
close match between Mendeleev's predictions and the actual properties of new elements showed how useful his periodic table could be.
What are some characteristics of the Noble gases?
colorless and odorless and extremely unreactive.
What is a metal?
elements that are good conductors of electric current and heat.
What are Transition Metals?
elements that form a bridge between the elements on the left and right sides of the table.
What is the most reactive nonmetal?
fluorine
What was the name of the element discovered in 1875 by a French chemist?
gallium
Where are the Transition Metals on the Periodic Table?
groups 3 through 12
What are the elements in Group 7A called?
halogens
In Mendeleev's periodic table, elements with similar properties were grouped
in the same column.
How does the reactivity of the Alkali Metals respond as you down the group?
increases from the top of Group 1A to the bottom.
Why is hydrogen group with the metals in Group 1A?
it has a single valence electron, it is grouped with other elements, such as lithium, that have only one valence electron.
What are the characteristics of a metal?
malleable, ductile, and high boiling points
What two elements are used in fertilizers?
nitrogen and phosphorus.
What is atomic mass unit?
one twelfth the mass of a carbon-12 atom.
What is each row on the Periodic Table called?
period
How are the differences in reactivity among the alkaline earth metals shown/
reactivity is shown by the way they react with water.
What is periodic law?
states many of the physical and chemical properties of elements usually recur in a manner with increasing atomic number
What does the atomic mass of an element depend on?
the distribution of an element's isotopes in nature and the masses of those isotopes.
What are some uses for the element gallium?
traffic signals and tiny light emitting diodes (LEDs)
What was Mendeleev's Prediction?
used the properties of elements located near the blank spaces in his table to predict properties for undiscovered elements.
