TCAP REVIEW LESSON 13 NOTESVoc. Foldable V

THE PERIODIC TABLE

ATOMIC MASS•The number of protons and neutrons in the nucleus of one atom of an element.

PERIODIC TABLE•Organizes information about all the known elements according to their properties.

ATOMIC NUMBER•The number of protons in its nucleus

PERIOD•Horizontal row in the periodic table

GROUP•A vertical column in the periodic table. Also known as the Chemical Family.

VALENCE ELECTRONS•The electrons in the outermost energy level of an atom.

REACTIVITY•How likely an element is to form compounds with other elements.

METALLOID•Have some properties of both metals and nonmetals.

NOBLE GAS•The elements in Group 18. Also known as the Inert Gases.

The Periodic Table Notes p.13• Mendeleev arranged the elements in order of their atomic masses• This arrangement of the elements was the first step in producing a useful scientific tool known as the periodic table• Today, elements are arranged in order of atomic number

Periods and Groups• Periods numbered from 1 to 7• Elements in each period increase in atomic number moving across the row from left to right• Groups are numbered from 1 to 18.• Elements in the same group have similar chemical properties• The number and arrangement of valence electrons tells how atoms of one element will combine with atoms of other elements to form compounds• Elements in groups 1 and 2 and 13-18 are the main group elements• Elements in Groups 3-12 are called transition element•With the exception of hydrogen, the elements on the left side of the periodic table are metals• Elements on the right side of the periodic table are nonmetals

Chemical Families• The most chemically active metals are in Group 1 (alkali metals)•Group 2 are called alkaline earth metals, highly reactive but are slightly less reactive and harder than Group 1•Group 3 through Group 12 are called Transition elements (hard solids; high melting points)•Metalloids: fall along a jagged line on the periodic table between the metals and nonmetals.•Noble Gasses: these gases are the least reactive elements.

The Periodic Table HW p. 11 1. Which of the following is the basis for arranging the elements in the modern periodic table?

a. alphabetical order c. number of protons

b. mass of atoms d. date of discovery

2. How many elements are listed in the modern periodic table?

a. 28 c. 72b. 60 d. more than 100

3. What do elements in the same column have in common?

a. similar chemical propertiesb. same number of protonsc. same atomic massesd. same size of their atoms