Q131. The property of metals by which they can be beaten into thin sheets is known as:
Basics of Everyday Science: RAS Prelims MCQs
200 RAS Prelims MCQs on the basics of everyday science test the scientific method, the laws of motion, chemical bonding and the cell theory. The questions use daily-life examples, such as the recoil of a gun and the orbit of a satellite, and the explanations give the principle behind each example so that you can reason out similar questions.
Practice questions based on the RPSC RAS Prelims syllabus. They follow the exam pattern but are not past-paper questions.
Showing 131–140 of 200 questions
Q132. Which of the following metals exists as a liquid at room temperature?
Explanation
Mercury is a unique chemical element that is classified as a metal but remains in a liquid state at standard room temperature and pressure. This behavior is due to its unique electronic configuration, which results in weak bonding between its atoms. Because it is a liquid and a good conductor, it has been widely used in thermometers, barometers, and various electrical switches.
Q133. Identify the only non-metal that exists as a liquid at room temperature.
Explanation
Most non-metals are either gases or solids at room temperature. Bromine is the only non-metallic element that exists as a liquid under standard conditions. It is a reddish-brown, volatile liquid with a sharp, unpleasant odor. Belonging to the halogen group, bromine is highly reactive and is commonly used in flame retardants, water treatment chemicals, and as a reagent in organic synthesis.
Q134. Consider the following statements about the reactivity series of metals:
I. Metals at the top of the series can displace metals below them from their salt solutions.
II. Gold and platinum are placed at the bottom of the series.
III. Metals below hydrogen in the series can easily liberate hydrogen gas from dilute acids.
Which of the above statement(s) is/are correct?
I. Metals at the top of the series can displace metals below them from their salt solutions.
II. Gold and platinum are placed at the bottom of the series.
III. Metals below hydrogen in the series can easily liberate hydrogen gas from dilute acids.
Which of the above statement(s) is/are correct?
Explanation
In the reactivity series, more reactive metals can displace less reactive ones from their compounds. Highly unreactive metals like gold and platinum are found at the bottom. However, only metals placed above hydrogen in the series are capable of displacing hydrogen from dilute acids to release gas. Metals below hydrogen, such as copper and silver, do not react in this way.
Q135. Metal oxides that exhibit both acidic and basic behaviors are known as:
Explanation
Amphoteric oxides are metallic oxides that show both acidic and basic characteristics. They can react with both acids and bases to produce salt and water. Common examples include aluminum oxide and zinc oxide. This dual reactivity is important in chemistry for identifying specific metal ions and is utilized in industrial processes where pH control and chemical neutralization are necessary for various reactions.
Q136. The process of heating carbonate ores strongly in limited air to convert them into oxides is termed:
Explanation
Calcination is a metallurgical process where carbonate ores are heated strongly in the absence or limited supply of air. This thermal treatment causes the ore to decompose, releasing carbon dioxide gas and leaving behind the metal oxide. This step is essential for preparing the ore for the subsequent reduction process, which eventually extracts the pure metal from its naturally occurring form.
Q137. Anodizing is a process of forming a thick oxide layer to prevent corrosion on which of the following metals?
Explanation
Anodizing is an electrochemical process used to increase the thickness of the natural oxide layer on the surface of aluminum parts. This thick, protective coating improves corrosion resistance, increases surface hardness, and allows for the application of dyes for decorative purposes. Unlike iron, which rusts when oxidized, the aluminum oxide layer is stable and adheres strongly to the metal, protecting it further.
Q138. Galvanization is a method of protecting steel and iron from rusting by coating them with a thin layer of:
Explanation
Galvanization is a widely used method for protecting iron and steel from atmospheric corrosion or rusting. It involves applying a thin, protective coating of zinc over the metal surface. Zinc acts as a sacrificial barrier; even if the coating is scratched, the zinc will corrode in preference to the underlying iron, effectively extending the lifespan of structural components and various hardware.
Q139. The most abundant metal in the Earth’s crust by weight is:
Explanation
Aluminum is the most abundant metallic element found in the Earth’s crust, making up approximately eight percent of its total weight. While it is extremely common, it is never found in its pure metallic form in nature; instead, it occurs in various minerals, most notably bauxite. Due to its abundance, lightweight, and corrosion resistance, it is a critical material for modern industry.
Q140. Arrange the following metals in decreasing order of their chemical reactivity:
I. Calcium
II. Potassium
III. Magnesium
IV. Sodium
Which of the following is the correct order?
I. Calcium
II. Potassium
III. Magnesium
IV. Sodium
Which of the following is the correct order?
Explanation
The reactivity of metals determines how easily they lose electrons to form positive ions. Potassium is the most reactive of the group, followed by sodium and then calcium. Magnesium is the least reactive among these four. Therefore, the correct sequence in decreasing order of their chemical reactivity is potassium, then sodium, followed by calcium, and finally magnesium at the end.Answer key for these questions
| Q | Correct answer |
|---|---|
| 131 | (c) Malleability |
| 132 | (d) Mercury |
| 133 | (c) Bromine |
| 134 | (a) I and II only |
| 135 | (d) Amphoteric oxides |
| 136 | (a) Calcination |
| 137 | (c) Aluminum |
| 138 | (a) Zinc |
| 139 | (d) Aluminum |
| 140 | (a) II, IV, I, III |
Key facts from Basics of Everyday Science
- Inductive reasoning draws a general conclusion from specific observations; a control variable is kept constant in an experiment; communicating the results is the last step of the scientific method.
- Newton’s second law relates force, mass and acceleration; the recoil of a gun illustrates the third law.
- Momentum is the product of mass and velocity; impulse is equal to the change in momentum.
- A satellite in uniform circular orbit is held by the centripetal force provided by gravity.
- Water (H₂O) and N₂ show covalent bonding; sodium chloride, MgO and CaF₂ are ionic.
- The classical cell theory does not say that all cells have a true nucleus.
Frequently asked questions
How many RAS Prelims practice MCQs are there on Basics of Everyday Science?
This page has 200 practice MCQs on Basics of Everyday Science (Science and Technology). Each has the correct answer, and most have an explanation.
What is the product of mass and velocity called?
Momentum. Newton’s second law says that the rate of change of momentum is equal to the force applied, and impulse is equal to the change in momentum of a body.
Which law explains the recoil of a gun?
Newton’s third law of motion. The gun pushes the bullet forward, and the bullet pushes the gun back with an equal and opposite force, which is felt as recoil.
What holds a satellite in a circular orbit?
The centripetal force provided by gravity. The Earth’s pull keeps changing the direction of the satellite’s velocity so that it moves in a circle and does not fly off in a straight line.