chapter 6 lesson 1 (Organizing the Elements) Flashcards
How did chemists begin to organize the known elements?
Early chemists used the properties of elements to sort them into groups.
How did Mendeleev organize his periodic table?
Mendeleev arranged the elements in his periodic table in order of increasing atomic mass.
How is the modern periodic table organized?
In the modern periodic table, elements are arranged in order of increasing atomic number.
the periodic law:
When elements are arranged in order of increasing atomic number, there is a periodic repetition of their physical and chemical properties.
What are the three broad classes of elements?
Metals, nonmetals and metalloids
Metals
generally good conductors of heat and electric current.
solids at room temperature, except for mercury
(metals) high luster, or sheen is
the metal’s ability to reflect light
Most metals are ductile
meaning that they can be drawn into wires
Most metals are malleable
meaning that they can be hammered into thin sheets without breaking
Nonmetal
Most nonmetals are gases at room temperature, including the main components of air—nitrogen and oxygen.
A few are solids, such as sulfur and
phosphorus.
One nonmetal, bromine, is a dark-red liquid.
Solid nonmetals tend to be brittle,
meaning that they will shatter if hit with a hammer.
are nonmetals poor conductors of heat and electric current?
yes they are poor conductors
Carbon, in the form of graphite, is an exception to this rule
Solid nonmetals tend to be brittle,
meaning that they will shatter if hit with a hammer.
Metalloids
generally has properties that are similar to those of metals and nonmetals. Under some conditions, metalloids may behave like metals. Under other conditions, they may behave like nonmetals.
