Periodic Table A

The vertical (up and down) columns in the Periodic Table are called

• groups

• towers

• periods

• atomic numbers

The Modern Periodic Table of Elements is arranged by

• atomic mass
• atomic number
• valence electrons
• number of isotopes

Sodium (Na) is found in period 

• 3
• 2
• 4
• 1

Sodium (Na) is found in group 

• 1
• 2
• 3
• 4

The atomic number tells you what?  READ THE ANSWERS CAREFULLY

• only the number of electrons
•  only the number of protons
• only the number of neutrons
• the number of both electrons and protons in an atom.

What does the atomic mass tell you? 

• Basically,the number of electrons and protons
• The number of neutrons
• Basically, the number of protons and neutrons
• The number of protons.

What does the 6 represent?

• atomic mass
• atomic number
• element name
• chemical symbol 

What does 12.011 represent?

• atomic mass
• atomic number
• element name
• chemical symbol 

The periodic table is a chart that organizes the elements based on their atomic properties. Elements in the periodic table are organized according to the periodic law. The periodic law states that chemical and physical properties of elements are periodic functions of their atomic numbers (the number of protons in the nucleus). As the atomic number of elements increases, different elements display similar characteristics at regular intervals.

Periodic law states that elements are arranged _______________________________________________________________.

• in alphabetical order.

• from largest to smallest.

• as periodic functions of their atomic numbers.

• there is no rhyme or reason.

In 1869, Dmitri Mendeleev developed the first periodic table, organizing the elements according to atomic weight. When he ordered the elements, he noticed that there were patterns of repeating properties. The modern periodic table sequences elements from left to right by atomic number.

This was the first person to organize a periodic table.

• Neils Bohr

• Dmitri Mendeleev

• Democritus

• Ernest Rutherford