Science Question Answer (1 Marks)

Chlorine is used in water purification process to make drinking water supply germ-free. Chlorine kills pathogens such as bacteria and viruses by breaking the chemical bonds in their molecules.

Sulphur and sodium are used in fire crackers. Fireworks contains metal salts and metal oxides which react to produce an array of colours.

An element which forms oxide which is acidic in nature is a non-metal. This is because nonmetallic oxides react with water to form acids.

Metals react with water to produce hydrogen gas. For example, sodium reacts with water to form sodium hydroxide and hydrogen gas.

Copper, aluminium and iron are used for making cooking utensils. Iron is used for making water boilers in factories.

Copper and aluminium are used for making electric wires due to their high ductility.

Carbon, in the form of Graphite is a good conductor of electricity. It conducts heat and electricity like a metal or a metalloid.

Gold and silver are used to make jewellery. This is because these metals are attractive due to their luster and rarity. These metals do not tarnish or react with air.

Iron is metal. It reacts with oxygen to form rust. Rust is chemically known as iron oxide. Since, rust is a metal oxide, it will be basic in nature.

Metals react with dilute acids to form metallic salts and hydrogen gas. For example, zinc reacts with dilute hydrochloric acid to form zinc chloride and hydrogen gas.

The property of metals to produce sound is called Sonority. Metals produce ringing sound and are sonorous in nature.

Copper does not react with dilute hydrochloric acid because it is below hydrogen in the reactivity series of metals.

Phosphorus is used in making fertilizers.

Carbon is used as a fuel in the form of coke or charcoal.

Copper is less reactive than iron. For example, if we put Iron nail into copper sulphate solution. Iron nail will displace copper from copper sulphate solution.

An element which forms oxide which is basic in nature is a metal. This is because metallic oxides are basic in nature and they react with water to form bases.

Following are the objects in our daily life which are made of metals:-

1. Utensils: The utensils we use daily are made from copper, aluminum and iron.
2. Jewellery: The jewellery is made from gold and silver.
3. Electric wires: These are made from copper and aluminum.
4. Mercury: It is used in thermometers.
5. Table salt: Sodium is used in making table salt.

Sodium reacts vigorously with dilute hydrochloric acid because it is above hydrogen in the reactivity series of metals.

Iodine is used to make purple coloured solution which is applied on cuts and wounds as an antiseptic. It is used in the treatment and prevention of wound infection.

Diamond is the hardest non-metal. It is made of carbon atoms.

Iron is a very important component of hemoglobin in our body. Hemoglobin is the substance in red blood cells that carries oxygen from our lungs and transports it throughout our body.