Science M.C.Q. [I MARKS]

Sodium and potassium both are extremely reactive and react with air as well as water vigorously. The reactions are highly exothermic and hence, the hydrogen gas evolved as byproduct catches fire.

Aluminium foil is prepared by beating it into sheets, i.e., property of malleability. Hence, aluminium foil is used for the given application.

When aluminium powder is heated with iron oxide, an exothermic reaction takes place with the formation of aluminium oxide and iron metal.

Copper cannot displace iron from iron sulphate solution because copper is less reactive than iron.

The product formed in the reaction of sulphur and oxygen is sulphur dioxide gas. When sulphur dioxide is dissolved in water sulphurous acid is formed. The sulphurous acid turns blue litmus paper red. Generally, oxides of non-metals are acidic in nature.

Aluminium reacts with hydrochloric acid as well as sodium hydroxide solution to produce hydrogen gas.

Assertion: Metals are sonorous.
Correct Reason: They are generally brittle in the solid state, they break into pieces when hammered.

Copper corrodes by oxidation in which it reacts with oxygen in the air to form copper oxide. Copper oxide then combines with carbon dioxide to make copper carbonate, which gives it a green colour. This process is called corrosion of copper.

Copper, Mercury, Silver and Gold are less reactive than hydrogen. Hence, they cannot displace hydrogen from the compounds like dilute acids, water, etc.

Metals are usually strong; they have high tensile strength. This means that metals can hold large weights without snapping or without breaking. As iron metal in the form of steel is a very strong and having a high tensile strength. Due to this, iron metal is used in the construction of bridges, building, railway lines, machines, vehicles etc. Rest of all are incorrect.

Carbon is a nonmetal. Nonmetals form oxides which are acidic in nature. Oxide of carbon is acidic.

A substance which cannot be broken down into two or more simpler substances by chemical reaction by applying heat, by light or by electricity, is called an element.

Mercury metal is in the liquid state at room temperature.

Carbon is a nonmetal. Nonmetals form oxides which are acidic in nature. Oxide of carbon is acidic and hence, its aqueous solution will turn blue litmus to red.

Mercury metal is in the liquid state at room temperature.

Ductility

Potassium is a metal. Metallic oxides are basic in nature.

 No, can copper will displace iron from iron sulphate solution. In a chemical reaction when a more reactive metal displaces the less reactive metal from its salt solution it is called, 'displacement reaction' e.g. Zinc can displace copper from its copper sulphate solution as zinc is more reactive than copper. Less reactive metal cannot displace the more reactive metal from its salt solution e.g. Copper cannot displace zinc from its solution zinc sulphate is copper is less reactive than zinc.

Polystyrene