Question

Classify the six underlined properties in the following paragraph as chemical or physical:

Fluorine is a pale yellowgas that reacts with most substances. The free elementmelts at -200⁰C and boils at -188 °C. Finely divided metals burn in fluorine with a bright flame. Nineteen grams of fluorine will react with 1.0 gram of hydrogen.

Short answer

Physical, Chemical, Physical, Physical, Chemical and Chemical respectively.

Step-by-step solution

Understanding what is physical and chemical change

Physical change is a type of change in which physical structure changes but chemical composition does not change.

Chemical change is a change in which chemical composition of a substance changes.

Analyzing underlined properties one by one

1. Gas –A physical state of matter
2. Reacts with most substances –Chemical property because reaction is required to check reactivity
3. Melts at -200⁰C –A physical property as no chemical reaction is required
4. Boils at -188⁰C –A physical property because boiling shows change of state
5. Metals burn in fluorine –A chemical property as chemical reaction is required
6. Nineteen grams of fluorine will react with 1.0 gram of hydrogen – A chemical property as chemical reaction is being done