Name the metal which is low in activity series and exist as liquid at room temperature.

Explanation

**Step-by-Step Solution:**

1. **Understanding the Activity Series:**
- The activity series is a list of metals arranged in order of decreasing reactivity. Metals that are more reactive can displace less reactive metals from their compounds.

2. **Identifying Low Activity Metals:**
- Metals that are low in the activity series include gold, platinum, silver, and mercury. Among these, we need to find out which one exists as a liquid at room temperature.

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