. Give reasons:-Plastic is used to cover electric wires.Silver and gold is used to make jewellery.A nail sinks in water and a leaf floats or water.Cooking vessels are made up of metals but handles are made up of wood.Metals lose their shine over a period of time.

. Give reasons:-Plastic is used to cover electric wires.Silver and gol

1.	. Give reasons:-Plastic is used to cover electric wires.Silver and gold is used to make jewellery.A nail sinks in water and a leaf floats or water.Cooking vessels are made up of metals but handles are made up of wood.Metals lose their shine over a period of time.
Answer» <p>1. Plastic helps dissipate the heat as well as prevent the wire from getting too hot and causing a fire. Plastic does a great job of insulating the conductor used in electrical systems. Without plastic, hot and neutral wires cannot be run in the same conductor or same wire.</p> <p>2. 2. Metals like gold, silver, platinum etc. have lustre, and these are less reactive, these metals cannot react with air water and acids and these metals are malleable and ductile. Due to these properties, these metals are called noble metals and they are used in jewellers.</p> <p>3. The density of snail is larger than the density of water and hence it sinks. While the density of leaf is much less than the density of water and hence it floats.</p> <p>4. Metals are good conductors of heat. When the vessel is heated it conducts heat and if the handle is made of metal, it will cause burns. So, the vessels are made of metal while the handle is wooden.</p> <p>5. Metals react with moist air and get oxidised and they lose their shining.</p>