Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
An element is a pure substance made up of only one kind of atom. It cannot be broken down into simpler substances by any physical or chemical means.
A symbol is a short-hand notation or an abbreviation used to represent a specific element. The modern system of symbols was proposed by J.J. Berzelius.
Rules for writing symbols: The first letter of a symbol is always capitalized. If the symbol has two letters, the second letter is always written in lowercase (e.g., Calcium is , not ).
Symbols from English names: Some elements use the first letter of their English name, such as Hydrogen (), Oxygen (), and Carbon ().
Symbols from two letters: When multiple elements start with the same letter, a second letter is added, such as Helium (), Calcium (), and Chlorine ().
Symbols from Latin names: Some symbols are derived from Latin names, such as Iron ( from Ferrum), Sodium ( from Natrium), Potassium ( from Kalium), and Gold ( from Aurum).
A symbol represents one atom of an element and also represents a definite mass of that element (atomic mass).
📐Formulae
💡Examples
Problem 1:
Why is the symbol for Sodium written as and not ?
Solution:
The symbol for Sodium is because it is derived from its Latin name Natrium. The symbol is already assigned to the element Sulfur.
Explanation:
Many elements in the periodic table use Latin roots to avoid confusion when multiple elements start with the same English letter.
Problem 2:
Distinguish between the notations and .
Solution:
represents the element Cobalt, whereas represents the compound Carbon Monoxide.
Explanation:
In chemical notation, a capital letter followed by a lowercase letter () indicates a single element. Two consecutive capital letters () indicate a compound made of two different elements: Carbon () and Oxygen ().
Problem 3:
Write the symbols for the following elements: Silver, Mercury, Lead, and Phosphorus.
Solution:
Silver: , Mercury: , Lead: , Phosphorus: .
Explanation:
Silver (), Mercury (), and Lead () use their Latin names, while Phosphorus uses the first letter of its English name.