Elements Reading Activity Page

Please read this passage carefully. Carry out the activity and answer the questions that follow.

Reading Activity

An element is a chemical substance which is made up of only one type of atom, so it cannot be broken down into any simpler form. For example, carbon is an element because it is made up of only carbon atoms. Copper is another example of an element. There are about ninety naturally occuring elements. Each one has its own kind of atom. Other elements have been made by scientists.

Each element is represented by a symbol. 'H' is the symbol for hydrogen, 'He' is the symbol for helium. Oxygen, Hydrogen, and Nitrogen are three elements which are colorless gases.

You will find a list of all elements with their symbols and other information on a chart called the Periodic Table of the Elements.

Activity

Look at the pictures of elements that you see on this web page. In your science notebooks draw a table with three columns with these headings:

1. Element
2. Physical Appearance
3. Symbol

Use the elements that you see in the pictures on this web page to complete the table.

Questions

1. Define  a) an element   b)the Periodic Table.
2. Why is copper an element?
3. How many kinds of atoms are there in carbon?
4. Name two elements that are metals, and name two elements that are not metals.
5. Carbon is a black solid. Describe  a) sulfur  b) mercury  c) silver
6. Name elements that are used to make a) jewelry  b) thermometers.
7. Name two elements from the list that are liquids, gases, and solids.

More About Elements

As we have discussed before Elements are the simpliest substances occurring in nature. An element is a substance whose atom are all the same.  So it is not possible to bread down an element chemically into simplier substances.

Physical Properties

About 115 elements are shown on the Periodic Table of the Elements.  Each element can be described by it's physical properties such as color, shininess, and hardness. Other Physical Properties used to describe elements are:

• Temperature at which the element melts (changes from a solid to a liquid).
• Temperature at which the elements boils (changes from a liquid to a gas).
• Density (mass of 1cm³ of the element).
• How well the element conducts electric current. (Is it a good conductor or poor conductor of electric?)

  Chemical Properties

Elements also have chemical properties. These properties include the way atom of elements join or combine with atoms of other elements in chemical reactions, and how readily these chemical reactions take place.

Examples of elements in chemical reactions are hydrogen (a gas), combined with oxygen (a gas) to form liquid water (H₂O).

When two or more elements combine they form a compound.  Water is a compound. A compound is made up of atoms of two or more different elements.