Question

Choose any element shown in green from group 1 on the periodic table by clicking on the element symbol. You should see details about the element that you chose appear at the bottom of the screen.

Select another element from group 1 by clicking on its symbol. Write the symbols and atomic numbers for each of the elements that you chose below:

Which element appears larger in the side-by-side comparison?
a) Element 1
b) Element 2
c) They appear the same size
d) Not enough information to determine

Answer 1

When comparing two elements from Group 1 on the periodic table, such as Lithium (Li) with an atomic number of 3 and Sodium (Na) with an atomic number of 11, Sodium (Na) would appear larger due to the increased number of electron shells as the principal quantum number (n) increases.

Step-by-step explanation:

To answer the question, we must understand how the periodic table is organized. The table is composed of rows called periods and columns referred to as groups. Group 1 elements are also known as the alkali metals. When we select two elements from Group 1, we should keep in mind that as we move down the group, the principal quantum number (n) increases, which generally results in a larger atomic radius. Therefore, if we chose Lithium (Li) with an atomic number of 3 and then Sodium (Na) with an atomic number of 11, we would observe that Sodium (Na) appears larger than Lithium (Li) in a side-by-side comparison due to the increased number of electron shells.

The atomic number is found above the symbol, and the atomic mass appears below the symbol on the periodic table for each element. For Lithium, the atomic number is 3, and for Sodium, the atomic number is 11. Based on the arrangement and the information on atomic radii, the answer is that Element 2 (Sodium) appears larger than Element 1 (Lithium).