Chemistry: Introduction to the Periodic Table
Elements, symbols, groups, periods, and atomic numbers
Chemistry: Introduction to the Periodic Table
Elements, symbols, groups, periods, and atomic numbers
Chemistry - Grade 6-8
- 1
What is the periodic table, and what information does it organize?
Think about what a table or chart helps scientists compare.
The periodic table is a chart that organizes all known chemical elements. It shows information such as element names, symbols, atomic numbers, and patterns in element properties. - 2
Find the element carbon on the periodic table. Write its chemical symbol and atomic number.
Carbon has the chemical symbol C and the atomic number 6. The atomic number tells how many protons are in one carbon atom. - 3
The square for oxygen shows the symbol O and the atomic number 8. What does the atomic number 8 mean?
Atomic number is linked to the number of protons.
The atomic number 8 means that every oxygen atom has 8 protons in its nucleus. - 4
What is the difference between an element's name and its chemical symbol? Give one example.
An element's name is the full word used to identify it, while its chemical symbol is a short abbreviation. For example, hydrogen is the element name and H is its chemical symbol. - 5
Elements in the same vertical column of the periodic table are in the same group. What is usually true about elements in the same group?
Look for patterns going down a column.
Elements in the same group often have similar chemical properties because their atoms have similar outer electron arrangements. - 6
Elements in the same horizontal row of the periodic table are in the same period. How many periods are shown on a standard periodic table?
A standard periodic table shows 7 periods. Each period is a horizontal row of elements. - 7
Lithium, sodium, and potassium are in Group 1. They are called alkali metals. Based on their location in the same group, what can you predict about them?
Elements in the same column often behave alike.
Lithium, sodium, and potassium likely have similar properties because they are in the same group. They are all metals and tend to react in similar ways. - 8
Which element has the atomic number 1? Write its name and symbol.
The element with atomic number 1 is hydrogen. Its chemical symbol is H. - 9
The atomic numbers of elements increase from left to right across each period. Which element comes immediately after boron, atomic number 5?
Add 1 to boron's atomic number.
Carbon comes immediately after boron because carbon has atomic number 6. - 10
Classify each element as a metal, nonmetal, or metalloid: aluminum, sulfur, silicon.
Aluminum is a metal, sulfur is a nonmetal, and silicon is a metalloid. - 11
What are noble gases, and where are they located on the periodic table?
Helium, neon, and argon are examples.
Noble gases are elements that usually do not react easily with other elements. They are located in the far right column of the periodic table, Group 18. - 12
An element tile shows the name sodium, the symbol Na, and the atomic number 11. How many protons does a sodium atom have?
A sodium atom has 11 protons because its atomic number is 11. - 13
Why are some chemical symbols not the same as the first letter or letters of the element's English name? Use sodium as an example.
Element symbols may come from different languages or historical names.
Some symbols come from older names or Latin names for the elements. Sodium has the symbol Na because it comes from the Latin word natrium. - 14
Look at these elements: helium, neon, argon. What do they have in common on the periodic table?
Helium, neon, and argon are all noble gases. They are in Group 18 on the far right side of the periodic table. - 15
Explain why the periodic table is useful for predicting how elements may behave.
Focus on patterns in rows and columns.
The periodic table is useful because elements are arranged in patterns. Elements near each other or in the same group often have similar properties, so scientists can use their location to predict behavior.