Periodic Table

Mendeleev organized the elements based on their

• atomic number.
• number of protons.
• atomic mass.
• number of neutrons.

In the modern periodic table, atomic number

• increases from top to bottom within each period.
• increases from left to right within each group.
• is the same within each group but not between groups.
• none of these

The shortest period in the periodic table is period

• 18
• 7
• 6
• 1

All but one of the elements on the left side of the periodic table are

• metalloids.
• liquids.
• metals.
• gases.

Which statement is true about any group in the periodic table?

• It includes metals, metalloids, and nonmetals.
• It includes elements with similar properties.
• It includes gases, liquids, and solids.
• It contains 18 different elements.

Mendeleev left spaces in his periodic table for unknown elements.

• True
• False

The modern periodic table is the same as Mendeleev’s table but with more elements.

• True
• False

The modern periodic table has more than 100 elements.

• True
• False

Elements called actinides are in period 7 of the periodic table.

• True
• False

Elements in the same period of the periodic table have similar properties.

• True
• False