Ghemical Properties of Ghemical Families
A chemical property is the potential of a substance to undergo
a chemical change or reaction. You cannot observe a
property of a substance without changing the substance. For
example, flammability is a substance's ability to catch fire.
Hydrogen is an extremely flammable element. other flammable
part of the
elements include nonmetals in the upper-right-hand
periodic table, such as oxygen.
An important chemical property of elements is reactivity.
Reactivity describes how likely an element is to react and form
bonds with other elements. The most reactive metals are
alkali metals in Group 1. Although hydrogen is the first element
and seems to be in Group 1, it is not an alkali metal. Hydrogen
is a distinctive element with a collection of properties that
closely resemble elements in any other group'
Group 2, the alkaline earth metals, are Very reactive but are
slighfly less reactive and harder than Group 1 metals. The
reactivity of both the Group 1 and Group 2 metals increases
increasing atomic number.
Groups 3 through 12 include the transition metals. A
transition elements is that they often form ions of various colors'
An ion is an atom that has a positive or negative charge. lons
form when atoms gain or lose electrons'
Halogens are nonmetals in Group 17. The halogens are the
reactive nonmetals. Reactivity in nonmetals increases aS atomic
number decreases, so fluorine is the most reactive nonmetal'
Halogens react with alkali metals to form salts'
Noble gases, Group 18, are the least reactive of all elements. At
one time, noble gases were considered inert-unable to
chemically. However, in 1962 scientists produced a substance
containing xenon (Xe) and fluorine (Fl). scientists have
many other substances involving noble gases since then.
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