A student dissolved some crystals of a salt in water.
The student added sodium hydroxide solution to the salt solution.
The student added sodium hydroxide solution until it was in excess.
Describe an additional test the student could do that would prove the salt contains calcium ions.

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

we need the questions , i may then you.

there is none because earth is stationary and flat.

i believe the answer is true.