Which of the following represents pure silver element?

• soft, conduct heat, opaque

• conduct heat, has metallic luster,brittle

• soft, conduct heat,has metallic luster

• conduct electricity, opaque, brittle

The liquid element which is bad conductor of heat and electricity is .............................

• bromine

• chlorine

• mercury

• lithium

The hardest element of the following is .................................

• ₁₃Al

• ₁₇Cl

• ₁₂Mg

• ₁₁Na

Copper is component of the bronze alloy, its percentage is .....................................

• 5 %

• 15 %

• 65 %

• 95 %

Sulphur is used in dry cells

• true

• false

Pure gold metal is harder than gold alloy.

• true

• false

Which of the following represent the composition of a solid alloy?

• 
• 
• 
• 

If the anion which composes the acid HClO is called hypochlorite, then the acid is called .............................

• hypochlorous acid

• hypochloric acid

• perchloric acid

• chlorous acid

Which of the following are properties of solid sodium hydroxide?

• it dissolves in water, and reacts with HCl acid

• it dissolves in water, and does not reacts with HCl acid

• it does not dissolve in water, and does not react with HCl acid

• it does not dissolve in water, and reacts with HCl acid

The molecular formulas of the following ions are correct EXCEPT .......................

• sulphate SO^-2₄

• phosphate PO^-3₄

• hydride OH^-

• nitrite NO^-₂