Question

If an element with Z = 120 is discovered, then which group of elements will it belong to?

• A. Alkaline earth metals
• B. Alkali metals
• C. Halogens
• D. Noble gases

Hint:

Remember the atomic numbers of the noble gases: He (2), Ne (10), Ar (18), Kr (36), Xe (54), Rn (86), and Og (118).
Any element with \(Z = \text{noble gas atomic number} + 1\) is an alkali metal (Group 1).
Any element with \(Z = \text{noble gas atomic number} + 2\) is an alkaline earth metal (Group 2).

Answer 1

The Correct Option is A

To determine the group of the periodic table to which an element with atomic number \(Z = 120\) belongs, we need to understand the configuration of elements in the periodic table. The periodic table is structured in such a way that elements are ordered by increasing atomic number (Z), which corresponds to the number of protons in an atom's nucleus.

The periodic table is divided into groups and periods. The groups (columns) are numbered from 1 to 18. Each group shares similar chemical properties because they have the same number of valence electrons. Here is a quick recap of the given options:

• Alkaline earth metals: Group 2
• Alkali metals: Group 1
• Halogens: Group 17
• Noble gases: Group 18

Now, let's break down how we determine the group for element \(Z = 120\):

1. Elements are filled sequentially with electrons around their nucleus. The order is determined by the Aufbau principle, where electrons fill sublevels starting at the lowest energy level.
2. To find the location of element \(Z = 120\), we observe the periodicity. After filling up to the element with \(Z = 118\) (Oganesson, a noble gas in Group 18), the next period would start with filling the new series which belongs to the s-block.
3. The s-block includes Group 1 (Alkali metals) and Group 2 (Alkaline earth metals). As \(Z = 119\) would fill the next s-block position corresponding to Group 1, it indicates element \(Z = 120\) would follow in Group 2.

Therefore, element \(Z = 120\) would be an alkaline earth metal, placing it in Group 2 of the periodic table. This conclusion is drawn based on the systematic ordering and electron configuration process of elements in the periodic table.