The Periodic Table

The Periodic Table

Lesson 3

In the late 1800s, a Russian chemist named
Dmitri Mendeleev presented a way to organize
all the known elements.
• He arranged elements in rows based on

increasing atomic mass.

• He arranged elements in columns based on

elements that shared similar physical and
chemical properties.

• He left blank spaces and predicted properties

for elements not yet discovered.

Organizing the Elements

In the modern periodic table, the elements are
arranged by increasing atomic number—not
atomic mass—and by periodic changes in
physical and chemical properties.

Organizing the Elements

Multiple Choice

Who created the first periodic table?

• Galileo

• Einstein

• Mosley

• Mendeleev

Multiple Choice

How did Mendeleev arranged his periodic table?

• By increasing atomic number

• By decreasing atomic mass

• By increasing atomic mass

• By decreasing atomic number

Multiple Choice

How is mendeleev periodic table similar to the one we use today?

• Mendeleev periodic table is similar to the one we use now because they both are able to predict properties of undiscovered elements. 

• Mendeleev periodic table is similar to the one we use now because they both were not able to predict properties of undiscovered elements. 

• Mendeleev periodic and the one today both used the atomic mass number to organize the periodic table.

• Mendeleev periodic table and the one today both used the exact same elements.

• The modern periodic table consists of boxes,

each containing information such as element
name, symbol, atomic number, and atomic
mass.

• The horizontal rows of elements in the

periodic table are called periods and are
numbered 1 through 7.

• The vertical columns in the periodic table are

called groups (also called families), and they
are numbered 1 through 18.

The Atom and the Periodic Table

• Group numbers 1 & 2 and 13-18 tells us how

many electrons are on the outermost energy
level.

• The group number correlates to the number

of electrons on the outermost level but for
groups 13-18 you need to minus 10 from the
number to get the number of electrons. For
example group 13-10 will give 3 electrons on
the outermost level.

The Atom and the Periodic Table

• Elements in the same group have similar

properties with a few exceptions.

• For example: If you look at group one

Hydrogen would have different properties
from the rest of the elements because it is a
non metal while the others are all metals.

The Atom and the Periodic Table

Match

Match to the correct answer

• The rows are called

• The columns are called

• There are ___ groups on the periodic table

• There are __ rows on the periodic table

periods

groups

18

7

• periods

• groups

• 18

• 7

Multiple Choice

Elements in the same group have similar

• Periods

• Protons

• Properties

• Levels

Match

Match each element to its number of valence electrons(s). Selection only includes elements 1-20.

• Silicon (Si)

• Magnesium (Mg)

• Nitrogen (N)

• Oxygen (O)

• Neon (Ne)

4

2

5

6

8

• 4

• 2

• 5

• 6

• 8

Scientists model the energy differences between
electrons by placing electrons in energy levels.

The Atom and the Periodic Table

An electron dot diagram
consists of the chemical
symbol of an element
surrounded by dots to
represent the number of
electrons in the outermost
energy level. Elements in the
same group have the same
number of electrons in their
outermost energy levels.

The Atom and the Periodic Table

An electron dot diagram can provide
information about how an atom might react,
the substance it could form, and why an atom
might be nonreactive.

The Atom and the Periodic Table

Multiple Choice

What can you determine about this element from its electron dot diagram?

• It is from group 1 and is reactive.

• It is from group 18 and is reactive.

• It is from group 1 and is unreactive.

• It is from group 18 and is unreactive.

Match

Match the electron dot diagram to the group

16

1

18

15

14

• 16

• 1

• 18

• 15

• 14

Multiple Choice

How many more electrons can energy level 4 hold than energy level 3?

• 18

• 32

• 14

• 50

Multiple Choice

What does it mean to be stable?

• To have 8 or more electrons except for H and He

• To max out all energy levels.

• To have 8 or 2 electrons on the outer level.

• To have 8 on the outer level except H or He which needs 2.

Knowing in which region an element is located
allows you to know its likely properties.

Regions of the Periodic Table

• Many of the same elements are found

throughout the universe.

• Many scientists think that hydrogen and helium

are the building blocks of all other elements.

• Atoms fuse within stars to produce heavier

elements with atomic numbers greater than
hydrogen and helium.

Elements in the Universe

Multiple Choice

Which best describes magnesium based on its location ?

• It is a nonmetal and most likely shiny

• It is a metal and most likely shiny

• It is a nonmetal and most likely a gas

• It is a metal and most likely a gas