Question

my question was attached in image.

pls tell me fast all three questions it is urgent.​

Answer 1

a.jewellery react with moisture present in the air and also with oxygen therefore it becomes black.

b.the process is called corrosion.

c.values shown by Anita are that jewellery kept in a scaled box and not to exposed in air.

Answer 2

a. The jwellery became black because it reacts with sulphur present in air .

b. The process is called oxidation.

c Anita was conscious about the scientific attribute ,and is caring friend .