Question

when heating liquid materials in laboratory glassware, a student should always
1 wear safety goggles
2 use benedicts solution
3 stopper the test tube
4 record the temperature of the liquid

Explanation:

When heating liquid materials in laboratory glassware, safety is of utmost importance. Wearing safety goggles protects the eyes from potential splashes or spills. Benedict's solution is used for a specific chemical test (detecting reducing sugars) and not relevant to general heating safety. Stopping a test tube while heating can cause pressure build - up and is dangerous. Recording the temperature is not a safety requirement that should "always" be done in the context of basic heating safety compared to eye protection.

Answer:

1. wear safety goggles