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Explore the chart that scientists use to organize all the known elements in the universe.
Imagine if everything in the entire universe—your toys, your dog, and even the stars—was made from a giant set of cosmic LEGO bricks. What if there was a secret map that showed you every single type of brick that exists?
Everything you see around you is made of elements. An element is a pure substance that cannot be broken down into anything simpler. Because there are over known elements, scientists needed a way to keep them organized. They created the Periodic Table. Think of it like a giant library where every 'book' is a different type of matter. Instead of being organized by title, these elements are organized by their properties and their 'ID numbers.' This map helps scientists predict how elements will behave, like whether they will explode when they touch water or if they are safe to breathe!
Imagine you are looking for a specific element on the table. 1. Look at the big chart with many colorful squares. 2. Each square represents one element. 3. Just like a map has a legend, the Periodic Table uses rows and columns to show which elements are 'cousins' and share similar traits.
Quick Check
What is the name of the chart scientists use to organize all the known elements?
Answer
The Periodic Table
Writing out long names like 'Molybdenum' every time would take forever! To save time, every element has a Chemical Symbol. This is a code made of one or two letters. The first letter is always capitalized. If there is a second letter, it is always lowercase. For example, the symbol for Hydrogen is , and the symbol for Helium is . Some symbols come from ancient names. Gold has the symbol because the old Latin word for gold was 'Aurum'!
Let's look at three common elements you might know: 1. Oxygen: Its symbol is a single capital letter, . 2. Calcium: Found in milk, its symbol is two letters, . 3. Iron: Used in buildings, its symbol is (from the Latin word 'Ferrum').
Quick Check
If an element symbol has two letters, like 'Na' for Sodium, which letter must be capitalized?
Answer
Only the first letter (N).
Every square on the Periodic Table has a special number called the Atomic Number. You can usually find this number at the very top of the square. This number is like the element's social security number or seat number in a theater. No two elements have the same atomic number! It tells us how many tiny particles called protons are inside one atom of that element. Hydrogen is the very first element, so its atomic number is . Oxygen has an atomic number of .
Let's use the atomic number to identify an element: 1. Find the square with the number at the top. 2. Look at the symbol below it, which is . 3. Read the name at the bottom: Carbon. 4. Because its number is , we know it is the 6th element on the map!
What does a Chemical Symbol represent?
Where is the Atomic Number usually located in an element's square?
True or False: Two different elements can have the same atomic number.
Review Tomorrow
Tomorrow, try to remember the symbol for Hydrogen and where you would look on a Periodic Table square to find its ID number.
Practice Activity
Go on a 'Symbol Hunt'! Look at a bottle of vitamins or a juice box and see if you can find symbols like (Calcium), (Iron), or (Potassium).