Acertain material has a normal freezing point of 10ºc and a normal boiling point of 70ºc. what state is the material in at room temperature (about 22ºc)? explain your answer.

Explanation:

A freezing point is defined as the point in which a liquid state of a substance changes into solid state.

Whereas boiling point is defined as the point at which liquid state of substance starts to convert into vapor state.

So, a substance is freezing at and boils at then it means at room temperature, that is, around the substance is present in liquid state.

This is because between the freezing and boiling point a substance will always exist in liquid state.

Thus, we can conclude that state of the material at room temperature is liquid.

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e

14 days is the half-life of phosphorus-32