One of the characteristic propertise of non-metals is that they

Options

A. are reducing agents
B. form basic oxides
C. form cations by electron
D. are electronegative

Explanation

To determine one of the characteristic properties of non-metals, we can analyze the given options step by step.

### Step 1: Understanding Non-Metals
Non-metals are elements that typically lack the characteristics of metals. They are generally poor conductors of heat and electricity and have higher electronegativities. Examples of non-metals include oxygen, nitrogen, and fluorine.

**Hint:** Remember that non-metals are elements that do not exhibit metallic properties.

### Step 2: Evaluating the Options
1. **Reducing Agent**: A reducing agent donates electrons in a chemical reaction. Non-metals typically do not act as reducing agents because they tend to gain electrons rather than lose them. Therefore, this option is incorrect.

**Hint:** Consider what a reducing agent does in a chemical reaction.

2. **Form Basic Oxides**: Non-metals generally form acidic or neutral oxides, not basic oxides. For example, carbon dioxide (CO₂) is an acidic oxide. Thus, this option is also incorrect.

**Hint:** Recall the types of oxides formed by non-metals.

3. **Form Cations by Electron Loss**: Non-metals usually do not form cations by losing electrons. Instead, they tend to gain electrons to achieve a stable electronic configuration. This option is incorrect as well.

**Hint:** Think about how non-metals behave in terms of electron transfer.

4. **Are Electronegative**: Non-metals have a high tendency to attract electrons, which is defined as electronegativity. This is a characteristic property of non-metals. Elements like fluorine, oxygen, and nitrogen are known for their high electronegativity.

**Hint:** Consider the definition of electronegativity and its significance in chemical bonding.

### Conclusion
Based on the analysis of the options, the characteristic property of non-metals is that they are electronegative. Therefore, the correct answer is:

**They are electronegative (Option D).**