Questions: 28. Which of the following elements have chemical properties similar to those of Li ? Na or Ca ? Explain.

Transcript text: 28. Which of the following elements have chemical properties similar to those of Li ? Na or Ca ? Explain.

Solution

Solution Steps

Step 1: Understanding Chemical Properties

Chemical properties of elements are primarily determined by their electron configurations, particularly the number of valence electrons. Elements with similar valence electron configurations tend to exhibit similar chemical properties.

Step 2: Analyzing the Electron Configuration of Li

Lithium (Li) has an atomic number of 3, and its electron configuration is \(1s^2 2s^1\). It has one valence electron in the outermost shell.

Step 3: Comparing Na and Ca

Sodium (Na) has an atomic number of 11, with an electron configuration of \(1s^2 2s^2 2p^6 3s^1\). Like lithium, sodium has one valence electron in its outermost shell.
Calcium (Ca) has an atomic number of 20, with an electron configuration of \(1s^2 2s^2 2p^6 3s^2 3p^6 4s^2\). Calcium has two valence electrons in its outermost shell.

Step 4: Determining Similarity in Chemical Properties

Since both lithium and sodium have one valence electron, they belong to the same group in the periodic table (Group 1, the alkali metals) and exhibit similar chemical properties. Calcium, on the other hand, belongs to Group 2 (the alkaline earth metals) and has different chemical properties due to having two valence electrons.