المادة وتركيبها: الفلزات

The video tutorial explains the classification of metals based on their chemical reactivity, particularly their ability to react with oxygen. Metals are divided into three groups: highly reactive, moderately reactive, and weakly reactive. Highly reactive metals like sodium and potassium lose their shine quickly and are stored under kerosene. Moderately reactive metals such as aluminum, iron, and copper form a layer of rust when exposed to air for days. Weakly reactive metals, including gold, silver, and platinum, are resistant to oxidation and are used in jewelry making.

Which of the following metals is stored under kerosene to prevent reaction with air?

• Iron

• Sodium

• Copper

• Gold

What happens to moderately active metals like iron when exposed to air for several days?

• They explode

• They become shiny

• They form a layer of rust

• They melt

Why are car parts often coated with grease?

• To change color

• To increase weight

• To prevent rusting

• To make them shiny

Which of the following metals is least likely to react with oxygen?

• Copper

• Iron

• Gold

• Aluminum

What is a common use for weakly active metals like silver and platinum?

• Construction materials

• Electrical wiring

• Jewelry making

• Fuel production