Question

science class 8 ch metals and non-metals.​

Answer 1

Answer:

1)sodium and potassium are stored in kerosene because they are highly reactive with water

2)silver became black in colour after some time because when silver reacts with CO2 a blackish colour substance is formed

Answer 2

Answer:

Q4 Sodium and potassium metals are kept in kerosene or in dry mineral oil . It protects these metals from being exposed to any moisture in the air that would cause these metals to react, potentially violently.

Q5 Silver turns black when kept in the air because it reacts with sulphur compounds such as hydrogen sulphide (H2S) present in air. The phenomenon is called corrosion and, for silver in particularly, is called tarnishing. The black substance formed is silver sulphide.