Unit C: Atoms, elements, and Compounds
6.1: A Table of the Elements
pg. 211
Key Concepts:
1. Elements cannot be broken down into simpler substances.
2. Metals and non-metals have characteristic physical properties.
- The Periodic Table is a table of Elements.
- It is used as a quick reference to distinguish elements from more complex
substances.
Element: a pure substance that cannot be broken down into simpler
chemical substance by any physical or chemical means.
Element symbol: an abbreviation for a chemical element.
Compound: a pure substance composed of two or more different elements
that are chemically joined.
- Elements are the smallest form of matter that can not be broken down to
any simpler form.
- The elements are identified on the periodic table by their name, and
symbols.
Ag
N
H
Au
– Silver (Latin name Argentum)
– Nitrogen
– Hydrogen
- Gold
- Water is not an element, it is not found on the periodic table. Water
consists of hydrogen and oxygen in 2: 1 ratio. Hydrogen and oxygen are
elements and are found on the periodic table.
- Water is a compound because it is made up of two elements, hydrogen and
oxygen.
- Any our substance that is composed of two or more different elements that
are chemically joined is called a compound.
Figure 2: When an electric current passes through water, the
particles of water are split apart, producing two gases –
hydrogen and oxygen.
- Elements are building blocks for all compounds.
- Elements are combined to form compounds, but there are certain
combinations that can occur. Not all elements can combine with each other.
- The periodic table shows the patterns of what elements can combine with
others.
Metals and Non-metals
Metal: an element that is lustrous, malleable, and ductile, and conducts heat
and electricity.
Non-metals: an element, usually a gas or a dull powdery solid, that does not
conduct heat or electricity.
Metalloid: an element that has properties of both metals and non-metals.
- Some elements appear metallic and others do not.
- Silver, copper and gold, have a shiny lustre.
- Lithium, sodium, and potassium have a white coating, no lustre, but when
cut they show a metallic sheen.
- Metals are elements that are found on the left and central side of the
periodic table.
- Non-metals are located on the right side of the periodic table.
- Most non-metals are gases, or dull powdery solids.
- Metals are good conductors will non-metals are insulators.
Evidence of Learning: Students can …
- describe elements and distinguish them from compounds.
- relate element symbols to elements and find them on the periodic table.
- describe metals, non-metals, and metalloids by their characteristic
properties.
Check Your Learning
Questions 1 – 10, page 215
Summary
- An element is a pure substance that cannot be broken down into a simpler
chemical substance by a physical or chemical means. Elements are the
building blocks of all substances and are arranged on the periodic table.
- A compound is a pure substance composed of two or more different
elements.
- A metal is an element that has luster, is a conductor, and is malleable and
ductile.
- A non-metal is an element that is usually a gas or a dull powdery solid.
Non-metals are usually poor conductors of heat and electricity.
- A metalloid has both metallic and non-metallic properties.