Which element does not form hydride upon heating with hydrogen?

Options

A. `Be`
B. `Mg`
C. `Sr`
D. `Ba`

Explanation

To determine which element does not form a hydride upon heating with hydrogen, we will analyze the behavior of the elements in the context of their chemical properties, particularly focusing on the alkali earth metals (Group 2 elements).

### Step-by-Step Solution:

1. **Identify the Group of Elements**:
We are looking at the alkali earth metals, which are located in Group 2 of the periodic table. This group includes elements such as Beryllium (Be), Magnesium (Mg), Calcium (Ca), Strontium (Sr), and Barium (Ba).

2. **Understand Hydride Formation**:
Generally, alkali earth metals react with hydrogen upon heating to form hydrides of the type MH₂, where M represents the metal. For example:
- Magnesium (Mg) reacts with hydrogen to form MgH₂.
- Calcium (Ca) reacts with hydrogen to form CaH₂.
- Strontium (Sr) and Barium (Ba) also form their respective hydrides.

3. **Examine Beryllium's Behavior**:
Beryllium (Be) is unique among the alkali earth metals. It has a high ionization energy and a small atomic size. The electrons in beryllium are held tightly by the nucleus, making it difficult for beryllium to lose its electrons and react with hydrogen to form a hydride.

4. **Conclusion**:
Since beryllium does not readily react with hydrogen to form a hydride, it stands out as the element that does not form a hydride upon heating with hydrogen.

5. **Final Answer**:
The element that does not form a hydride upon heating with hydrogen is **Beryllium (Be)**.