An element X has atomic number 19.What will be the formula of its oxide?

Options

A. `X_(2)O`
B. XO
C. `XO_(2)`
D. `X_(2)O_(3)`

Explanation

To determine the formula of the oxide for the element X with atomic number 19, we can follow these steps:

### Step 1: Identify the Element
The atomic number 19 corresponds to the element Potassium (K).

### Step 2: Write the Electronic Configuration
The electronic configuration of Potassium (K) can be written as:
- 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹
This shows that Potassium has one electron in its outermost shell (4s).

### Step 3: Determine the Oxidation State
Potassium, having one electron in its outermost shell, tends to lose that electron to achieve a stable electronic configuration similar to the nearest noble gas (Argon). Therefore, Potassium will have an oxidation state of +1 (K⁺).

### Step 4: Identify the Oxide Ion
The oxide ion (O²⁻) has a charge of -2. This means it has gained two electrons to achieve a stable electronic configuration.

### Step 5: Balance the Charges
To balance the charges between the Potassium ion (K⁺) and the oxide ion (O²⁻), we need two Potassium ions for every one oxide ion:
- 2 K⁺ + O²⁻ → K₂O

### Step 6: Write the Formula of the Oxide
Thus, the formula of the oxide for the element X (Potassium) is K₂O.

### Final Answer
The formula of the oxide for the element with atomic number 19 is K₂O.

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