metals and non metals class 10

which metal is found in free state

• gold

• platinium

• silver

• iron

what is the role of dielectric constant ?

• to weaken the force of attraction between ions of ionic compounds .

• to break the force of attraction between ions of ionic compounds.

• to increase the force of attraction between ions of ionic compounds .

• both a and b

which is the lightest liquid metal ?

• lithium

• caesium

• mercury

• non of these

generally metals react with acid and liberate hydrogen gas but with which acid metals does not liberate hydrogen gas ?

• acetic acid [ ch3cooh ]

• hydrochloric acid [ hcl ]

• nitric acid [ hno3 ]

• carbonic acid [ h2co3 ]

metals does not liberate h2 gas with hno3 as it is a very -

(a)  

what is amalgam ?

• alloy of a metal with iron

• alloy of a metal with mercury

• alloy of a metal with brass

• alloy of a metal with magnalium

which metal is the hardest known substance ?

• bromine

• sodium

• neon

• diamond

Only a few reactive metals react with hydrogen to form ?

• metal hydrates

• metal hydrides

• metal hydrites

• none of these

what is galvanization ?

• applying a coating of zinc to prevent form corrosion

• applying a coating of aluminium to prevent form oxidation

• applying a coating of iron to prevent form corrosion

• applying a coating of both aluminium and zinc to prevent form corrosion

an electrolytic process for producing thick oxide coatings, usually on aluminium and its alloys -

• electrolysis

• nuclear magnetic resonance

• anodizing

• electrodising