What Are Periods & Groups In The Periodic Table? | Properties of Matter | Chemistry | FuseSchool

Summary

The Periodic Table organizes elements based on recurring properties, arranged in periods (rows) and groups (columns). As you move across periods, elements share the same number of energy shells, while elements in the same group have similar chemical properties due to having the same number of valence electrons. For example, Group 7 elements, such as Fluorine and Chlorine, all have 7 valence electrons and exhibit similar reactivity. The number of energy shells increases as you move down the table, explaining the gradual change in properties within each group. This structure helps identify patterns in element behavior.

Takeaways

• 😀 The Periodic Table organizes elements based on recurring properties.
• 😀 Elements are arranged in PERIODS (rows) and GROUPS (columns).
• 😀 Elements in the same PERIOD share the same number of energy shells.
• 😀 Elements in the same GROUP have the same number of electrons in their outermost shell.
• 😀 Valence electrons are the outermost electrons and play a key role in chemical reactions.
• 😀 The number of valence electrons governs an element's reactivity.
• 😀 Elements in the same GROUP exhibit similar chemical properties due to the same number of valence electrons.
• 😀 The GROUP number helps identify how many electrons are in the outer shell.
• 😀 Elements in Group 7, like Fluorine, Chlorine, Iodine, Bromine, and Astatine, all have 7 valence electrons.
• 😀 As you move down a GROUP, the outer electrons are located in different energy shells, showing a gradual change in properties.

Q & A

What is the periodic table and why is it called that?

The periodic table is a chart that organizes chemical elements based on recurring properties. It is called the 'periodic' table because elements with similar properties appear periodically as you move across periods and down groups.

What are periods in the periodic table?

Periods are the horizontal rows in the periodic table, running from left to right. Elements in the same period share the same number of energy shells.

How do energy shells relate to periods?

Each period in the periodic table represents a new energy shell. As you move down from period to period, the number of energy shells increases.

What are groups in the periodic table?

Groups are the vertical columns in the periodic table. Elements in the same group share similar chemical properties because they have the same number of electrons in their outermost shell.

What are valence electrons?

Valence electrons are the electrons in the outermost shell of an atom. These electrons are responsible for an element's chemical reactivity and bond formation.

How do valence electrons affect an element's reactivity?

The number of valence electrons determines an element's reactivity. Elements with the same number of valence electrons have similar reactivity, which is why elements in the same group have similar properties.

How can you determine the number of valence electrons in an element?

The group number of an element can tell you how many electrons are in its outermost shell. For example, elements in Group 7 have 7 valence electrons.

Why do elements in the same group have similar chemical characteristics?

Elements in the same group have the same number of valence electrons, which governs their chemical reactivity and results in similar chemical characteristics.

Can you give an example of elements with similar properties from the same group?

An example is Group 7, which includes Fluorine, Chlorine, Iodine, Bromine, and Astatine. All these elements have 7 valence electrons and share similar chemical properties.

What happens to the properties of elements as you move down a group?

As you move down a group, the elements show a gradual change in properties. This is because the number of energy shells increases, and the outermost electrons are farther from the nucleus.