Which of these elements is chemically similar Ca?
a. Mg
b. B
c. Ar
d. Br
e. Al
The correct answer and explanation is:
The correct answer is: a. Mg (Magnesium)
Explanation:
Calcium (Ca) and Magnesium (Mg) are chemically similar because they both belong to Group 2 of the Periodic Table, also known as the alkaline earth metals.
Group Similarities:
Elements in the same group have the same number of valence electrons, which largely determines their chemical behavior. Both calcium and magnesium have two electrons in their outermost shell (valence shell). This makes them likely to form +2 ions (Ca²⁺ and Mg²⁺) by losing these two electrons during chemical reactions.
Alkaline Earth Metals:
The alkaline earth metals include:
Beryllium (Be), Magnesium (Mg), Calcium (Ca), Strontium (Sr), Barium (Ba), and Radium (Ra)
These metals share the following properties:
- They are shiny, silvery-white metals.
- They are somewhat reactive, especially with water (increasing reactivity as you move down the group).
- They form basic (alkaline) oxides and hydroxides.
- They commonly form ionic compounds.
Since magnesium is just above calcium in the periodic table, they have similar atomic structures, with calcium having an additional electron shell. However, their chemical properties remain closely related.
Why the Other Options Are Not Similar:
- b. B (Boron): A Group 13 element; metalloid with 3 valence electrons.
- c. Ar (Argon): A noble gas (Group 18), very unreactive, completely different behavior.
- d. Br (Bromine): A halogen (Group 17), a reactive non-metal forming −1 ions.
- e. Al (Aluminum): A post-transition metal in Group 13, forming +3 ions.
These elements differ in their group, valence electron count, and general chemical behavior, making them chemically dissimilar to calcium.
Conclusion:
Magnesium (Mg) is chemically similar to calcium because they are both alkaline earth metals in the same group with similar physical and chemical properties.