A helium atom on losing an electron becomes

Options

A. `alpha -` particle
B. hydrogen atom
C. positively charged helium ion
D. negatively charged helium ion

Explanation

To solve the question "A helium atom on losing an electron becomes," we can follow these steps:

### Step 1: Understand the structure of a helium atom
A helium atom has an atomic number of 2, which means it has 2 protons and, in its neutral state, it also has 2 electrons.

**Hint:** Recall that the atomic number indicates the number of protons and, in a neutral atom, the number of electrons is equal to the number of protons.

### Step 2: Determine what happens when an electron is lost
When a helium atom loses one electron, it will have 2 protons and only 1 electron remaining. This results in a net positive charge because there are more protons than electrons.

**Hint:** Remember that losing an electron results in a positive charge, as electrons are negatively charged.

### Step 3: Identify the resulting ion
The resulting ion from the loss of one electron from a helium atom is known as a cation. Specifically, it is referred to as a positively charged helium ion, denoted as He⁺.

**Hint:** Cations are formed when atoms lose electrons, leading to a positive charge.

### Step 4: Conclusion
Thus, when a helium atom loses an electron, it becomes a positively charged helium ion (He⁺).

**Final Answer:** The correct answer is a positively charged helium ion (option C).