Which is an example of making a quantitative observation?
measuring the mass of metal used in a reaction
recording the color of a solid formed in a reaction
describing a liquid as having a slippery feel
rating an odor on how nice it smells

measuring the mass of metal used in a reaction

Explanation: Qualitative observation involves the data that can be observed with our senses such as sight, smell, touch, taste, and hearing. It does not involve measurement or numbers.

Quantitative observation involves the measurement of numbers and require the use of instruments.

Mass is measured by use of weighing balance and thus is a quantitative observation.

Recording the color of a solid formed in a reaction is observed by sight and thus is a qualitative observation.

Describing a liquid as having a slippery feel is observed by touch and thus is a qualitative observation.

Rating an odor on how nice it smells is felt by smell and thus is a qualitative observation.

A "quantitative" observation is one that involves measuring something, and is usually reported in terms of numbers ("quantities").

Measuring a mass of metal is a good example of a quantitative observation.

they start with the same