Classify the following into elements, compounds and mixtures.
Nitrogen, Carbon dioxide, sand, washing soda, fruit juice, soda water, mercury, concrete, argon, saline water, bromine and sugar.

Explanation

To classify the given substances into elements, compounds, and mixtures, we can follow these steps:

### Step 1: Understand the Definitions
- **Element**: A pure substance that cannot be broken down into simpler substances by chemical means. Examples include nitrogen and mercury.
- **Compound**: A substance formed when two or more elements are chemically bonded together. Compounds can be broken down into their constituent elements by chemical methods. Examples include carbon dioxide and sugar.
- **Mixture**: A combination of two or more substances that are not chemically bonded. Mixtures can be separated by physical methods. Examples include sand and fruit juice.

### Step 2: Classify Each Substance
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