Question

unit 5 comprehensive quiz l
which three elements have properties most similar to one another?
potassium, calcium, and scandium - which are adjacent to each other in the fourth row, or period, of the periodic table
magnesium, calcium, and strontium - which are adjacent to each other in the second column, or group, of the periodic table
cadmium, calcium, and carbon - which are near one another in an alphabetical list of the elements
oxygen, chlorine, and helium - which are located at or near the upper right corner of the periodic table

Explanation:

Elements in the same group (column) of the periodic table have similar chemical properties. Magnesium (Mg), calcium (Ca), and strontium (Sr) are in Group 2 (the alkaline earth metals).
Potassium (K) is an alkali metal (Group 1), calcium (Ca) is an alkaline earth metal (Group 2), and scandium (Sc) is a transition metal (Group 3) - different groups, different properties.
Cadmium (Cd) is a transition metal (Group 12), calcium (Ca) is an alkaline earth metal (Group 2), and carbon (C) is a non - metal (Group 14) - different groups, different properties.
Oxygen (O) is a chalcogen (Group 16), chlorine (Cl) is a halogen (Group 17), and helium (He) is a noble gas (Group 18) - different groups, different properties.

Answer:

Magnesium, calcium, and strontium— which are adjacent to each other in the second column, or group, of the periodic table.