This chapter would help students classify the elements into metals and non-metals. Students also learn about the properties of the elements which builds a strong foundation of the basic Chemistry. Our Chemistry Experts have provided below important NTSE questions to help students prepare better for the exam.
Q. Naturally occurring substances from which a metal can be profitably (or economically) extracted are called-
Ans: (b) Ores
Sol: Ores are minerals from which metals can be extracted profitably and conveniently.
Q. Froth floatation method is used for the concentration of –
(a) Oxide ores
(b) Sulphide ores
(c) Sulphate ores
(d) Halide ores
Ans: (b) Sulphide ores
Sol: Pine oil is added to powdered ore and water. Air is passed to create froth that carries higher sulphide ore particles with it.
Q. Metals generally are –
(a) Reducing agents
(b) Oxidizing agent
(c) Both oxidising and reducing agents
(d) None of these
Ans: (a) Reducing agents
Sol: Reducing agents get preferentially oxidized since metals have a tendency to lose electrons so they are good reducing agents.
Q. Which of the following methods is suitable for preventing an iron frying pan from rusting?
(a) Applying grease
(b) Applying paint
(c) Applying a coating of zinc
(d) All of the above.
Ans: (C) Applying a coating of zinc
Sol: As grease and paint are not good options for heat during cooking so galvanization (Coating of Zinc) is the best option).
Q. Which observation most strongly suggests that a solid element X is a non–metal?
(a) X forms an acidic oxide.
(b) X has a high melting point.
(c) X is a conductor of electricity.
(d) X reacts vigorously with chlorine.
Ans: (a) X forms an acidic oxide.
Sol: Non metallicoxide are acidic in nature.
Before you learn these questions and answers, go through the chapter for a better understanding of the chapter. For more chapter-wise questions and answers stay tuned with NTSEGuru.in