Two elements that have similar properties because they have the same number of valence electrons are

Options

A. C and CI
B. Ca and Ga
C. Si and S
D. S and O

Answer

To answer the question regarding two elements that have similar properties because they have the same number of valence electrons, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Valence Electrons**: Valence electrons are the electrons in the outermost shell of an atom. The number of valence electrons determines how an element will react chemically and its bonding behavior.

2. **Identify Groups in the Periodic Table**: Elements that belong to the same group (vertical column) in the periodic table have the same number of valence electrons. For example, Group 1 elements have 1 valence electron, Group 2 elements have 2 valence electrons, and so on.

3. **Select Two Elements from the Same Group**: Choose any two elements from the same group. For instance:
- Group 1: Sodium (Na) and Potassium (K) both have 1 valence electron.
- Group 16: Oxygen (O) and Sulfur (S) both have 6 valence electrons.

4. **Confirm Similar Properties**: Since both elements in the selected pair have the same number of valence electrons, they will exhibit similar chemical properties. For example, Sodium and Potassium are both alkali metals and react similarly with water.

5. **Final Answer**: Based on the above reasoning, one possible answer could be:
- **Oxygen (O) and Sulfur (S)** as they both belong to Group 16 and have 6 valence electrons.