Elements and Compounds

A ________ is a pure substance that cannot be separated into simpler substances by physical or chemical means.

• Compound

• Mixture

• Element

• Chromatography

On Earth, ____ elements occur naturally.

• 5

• 15

• 87

• 91

Which of the following does not occur naturally on Earth?

• Nobelium

• Oxygen

• Copper

• Gold

Which scientist created the periodic table of elements?

• Robert Hooke

• Dimitri Mendeleev

• Anton van Leeuwenhoek

• Issac Newton

The _____________ organizes the elements into a grid of horizontal rows called periods and vertical columns called groups.

• Hierarchy of Organization

• The Periodic Table of Elizabeth

• The Periodic Table of Elements

• The Periodic Table of Mrs. Womble is the Best

The table is called "___________" because the pattern of similar properties repeats as you move from period to period.

• Elemental

• Tabular

• Tubular

• Periodic

You know that _______ is classified as pure substances and mixtures.

• Elements

• Compounds

• Matter

• Energy

A ____________ mixture is one that does not blend smoothly throughout and in which the individual substances remain distinct.

• Heterogeneous

• Homogeneous

Homogeneous mixtures are also referred to as ______

• Elements

• Mixtures

• Heterogeneous

• Solutions

Today, there are approximately _____ million known compounds, and new compounds continue to be developed and discovered at the rate of 100,000 per year.

• 1

• 10

• 100

• 5