Question

1. choose the correct scientific notations.

elements in a(n) ____ have similar properties due to valence electrons.
group
ion pairing
isotope pairing
period

Explanation:

Elements in a group (vertical column in the periodic table) have the same number of valence electrons. Valence electrons determine the chemical properties of an element. For example, Group 1 elements (alkali metals) all have 1 valence electron and show similar reactive behavior. Ion - pairing refers to the association of ions in a solution. Isotope - pairing is not a standard term related to element properties in this context. Elements in a period (horizontal row) have increasing atomic number and different valence electron configurations across the period.

Answer:

group