NCERT Class 9 Science — Chapter 2: Is matter around us pure?

With reference to 'Alloys', consider the following statements: 1. They are considered mixtures because they show the properties of their constituents. 2. They can be separated into their components by physical methods. 3. They have a fixed composition and cannot vary. Which of the statements given above is/are correct?

Consider the following statements regarding the properties of metals: 1. They are generally brittle and non-ductile. 2. They are generally good conductors of heat and electricity. 3. They are sonorous. Which of the statements given above is/are correct?

Consider the following statements about elements: 1. The majority of elements are solids. 2. Only two elements are in the gaseous state at room temperature. 3. Gallium and Cesium remain solid even at temperatures well above 303 K. Which of the statements given above is/are correct?

In the classification of colloids, 'Cheese' and 'Butter' are examples of:

Consider the following statements regarding the burning of wood: 1. It involves the conversion of wood into new substances like ash and smoke. 2. It is a physical change. 3. It is an irreversible process. Which of the statements given above is/are correct?