Refer to the periodic table, and give the period and group number for each of these elements. (Use the standard U.S. notation for group numbers, e.g., 2A or SB.) (a) potassium – Period 4, Group 1A (b) xenon – Period 5, Group 8A (c) neon – Period 2, Group 8A
The Correct Answer and Explanation is:
Let’s break down the information for each element:
(a) Potassium (K)
- Period: Potassium is found in Period 4 of the periodic table. This is because it is located in the fourth row, starting from the top.
- Group: Potassium belongs to Group 1A. Group 1 elements are known as alkali metals, and potassium is one of them. These elements have a single electron in their outermost shell, making them highly reactive and typically forming +1 ions.
(b) Xenon (Xe)
- Period: Xenon is found in Period 5. It’s located in the fifth row of the periodic table.
- Group: Xenon belongs to Group 8A. This group is known as the noble gases, which include elements like helium, neon, and argon. These gases are chemically inert, having a full outer electron shell, which makes them stable.
(c) Neon (Ne)
- Period: Neon is located in Period 2. It is in the second row of the periodic table.
- Group: Neon belongs to Group 8A as well. Like xenon, neon is a noble gas, and being part of this group means it has a full outer electron shell, which accounts for its lack of reactivity.
Explanation of the Periodic Table Notation:
- Periods: These are the horizontal rows in the periodic table. Each period represents a new electron shell being added as you move from left to right.
- Groups: These are the vertical columns in the periodic table. Elements in the same group share similar chemical properties because they have the same number of valence electrons. Groups 1A and 8A are particularly significant because Group 1A elements are highly reactive metals, while Group 8A elements are inert gases.
In summary:
- Potassium is in Period 4, Group 1A.
- Xenon is in Period 5, Group 8A.
- Neon is in Period 2, Group 8A.
