Science questions in short. [2 marks ]

Copper and aluminium are used for making cooking utensils and water boilers for factories.

Connecting wires are made up of copper and aluminium because these metals are ductile and good conductor of electricity.

Metals are sonorous. Sonorous means metals make noise on striking with another metal. So bells used in temples are made up of metals and not of wood which is a non-metal.

Lemon pickle is acidic in nature. Aluminium metal is highly reactive in nature. If the pickle is stored in an aluminium container, the acid present in pickle will react with aluminium and the pickle will be spoiled.

The property by which iron metal can be hammered to make objects of different shapes such as axe, spade etc. is called Malleability. As a result of high malleability, iron can be flattened or beaten into thin sheets and desired objects can be made by using it.

The two metals which are soft and easily cut with a knife are Sodium and potassium. The freshly cut surface of these metals is shiny but it tarnishes quickly on contact with air. This is because these metals react with oxygen and water and becomes dull grey in colour.

The metal which is liquid at room temperature is Mercury (Hg). Another metal called Gallium also exists as liquid at room temperature. Its melting point is very low and it changed into a liquid when touched. The nonmetal which is liquid at room temperature is Bromine.

Magnesium has important role in photosynthesis because it forms the central atom of chlorophyll. Plants begin to degrade the chlorophyll in old leaves without sufficient amounts of magnesium.

Oxygen is the nonmetal which is essential for maintaining life and is inhaled during breathing. Oxygen is brought into our lungs via breathing. It is then transported by red blood cells to the entire body to be used to produce energy.

We don’t use non-metals for making jewellery because non-metals are not lustrous. We use metals for making jewellery because they are lustrous.

Iron can react with steam because iron is less reactive so it reacts with steam.

Non-metals react with oxygen to form nonmetallic oxides. These oxides differ from metallic oxides because they are acidic in nature. Nonmetallic oxides react with water to form acids. For example, Sulphur is a nonmetal. Sulphur dioxide is acidic in nature.

We cannot hold hot metal pan directly because metals are good conductor of heat and they hurt us. So we use plastic or wooden handle to hold the hot metal pan because plastic and wood are bad conductor of heat and they do not hurt us.

Metals react with water to produce hydrogen gas. Phosphorus cannot be kept open in the air because it combines with oxygen so easily that it catches fire automatically. For safety, phosphorus is stored under water in chemical laboratories.

The property of metals which enables them to be drawn into wires is called Ductility. Due to this property metals can be stretched without breaking and drawn into thin wires. For example, Copper metal is used for making electric wires because it is highly ductile in nature.

Metals have quality to reflect light. As a result, metals are lustrous in nature. It makes metals attractive due to their luster and rarity. Hence, metals like, gold and silver are used to make jewellery. These metals do not tarnish or react with air.

Metals are sonorous because they produce a unique sound when something hard strikes their surface. As a result, metals are used in making bells or gongs.

Copper metal is used for making electric wires because it is highly ductile in nature. It is a good conductor of electricity. The property of metals which enables them to be drawn into wires is called Ductility. Due to this property metals can be stretched without breaking and drawn into thin wires. Metals have free electrons which makes them good conductors of heat and electricity.

The chemical property which can be used to distinguish between a metal and a nonmetal is the formation of positive ions by metals. Metals form positive ions whereas nonmetals form negative ions. As a result, oxides of metals are basic whereas the oxides of nonmetals are acidic in nature.

Diamond is a non-metal which is very hard. Diamond is an allotrope of carbon.

Yes, Sulphur dioxide is acidic in nature because oxides of non-metal are acidic in nature.

Metals react with oxygen to form metallic oxides. These metallic oxides are basic because they react with water to form bases. For example, Magnesium is a metal and magnesium oxide are basic in nature.

Copper cannot displace zinc from zinc sulphate solution. Zinc is placed above copper in reactivity series of metal. Hence, it will be able to replace copper from copper sulphate solution. Zinc + Copper Sulphate → Copper + Zinc sulphate

Metals react with oxygen to form metallic oxides. These metallic oxides are basic because they react with water to form bases. On the other hand, nonmetals react with oxygen to form nonmetallic oxides. These oxides differ from metallic oxides because they are acidic in nature. Nonmetallic oxides react with water to form acids.

Graphite is a good conductor of electricity. Graphite is made of carbon. Its valence electrons are free to move. As a result, graphite is able to conduct electricity which makes it useful for making electrode in a cell.

Ductility:- The property of metals which enables them to be drawn into wires is called Ductility. Due to this property metals can be stretched without breaking and drawn into thin wires.

Copper cannot displace zinc from its salt solution because copper is less reactive than zinc. More reactive metal displaces less reactive metal from its salt solution.

Aluminum is used to make thin foils for packaging medicines, chocolates and food items. This is because it provides a complete barrier to light, oxygen, moisture and bacteria.

Mercury is used for making thermometers. It is liquid at room temperature and is a very good conductor of heat. Even a slightest change in temperature can be noted by using mercury.

Immersion rods for heating liquids are made of metallic substances because metallic substances are good conductors of electricity and heat. Metals have free electrons which makes them good conductors of heat and electricity.

Iron: It is used to make doors and windows.
Copper: It is used to make electric wires.
Gold: It is used to make ornaments.
Silver: It is also used to make ornaments.

No. Copper cannot displace zinc from its salt solution because copper is less reactive than zinc. More reactive displaces less reactive metal from its salt solution.

Zinc is more reactive than iron. Zinc is placed above iron in the reactivity series. For example, Zinc can displace iron from ferrous sulphate solution to form zinc sulphate and iron.

Zinc is placed above iron in the reactivity series of metals. Hence, zinc will be able to displace iron for iron sulphate solution.

Metals are sonorous because they produce a unique sound when something hard strikes their surface. As a result, metals are used in making bells or gongs.

Zinc is most reactive among three metals and copper is least-reactive metal. Reactivity of iron is in between zinc and copper. So, zinc metal can displace the other two metals from their salt solutions.

Zinc is used to galvanize iron to protect it from rusting. In this process, a thin layer of zinc is coated on the surface of iron. Zinc acts as a barrier against corrosion so that iron does not come in contact with water or moisture in the air.

There is no colour change on adding copper turning in zinc sulphate solution because copper is less reactive than zinc and it cannot displace zinc from its salt solution. So, displacement reaction does not take place.