Metals & Nonmetals Quiz: Can You Tell Them Apart?

Mercury (Hg) exists in the liquid state at room temperature and pressure. Unlike sodium (Na), silver (Ag), and chromium (Cr), which are all solid metals, mercury has a low melting point of -38.83 degrees Celsius (-37.89 degrees Fahrenheit), allowing it to remain in a liquid state under normal conditions.

The element that fits the given description is sodium (Na). Sodium is soft and can be easily cut with a knife. It is highly reactive to air and cannot be kept open in air, as it quickly reacts with oxygen to form sodium oxide. Additionally, sodium reacts vigorously with water, producing hydrogen gas and sodium hydroxide.

When metal A displaces metal B in a solution of its salt, it indicates that metal A is more reactive than metal B. This is because a more reactive metal has a higher tendency to displace a less reactive metal from its compound. Therefore, metal A is able to replace metal B in the salt solution, suggesting that it is more reactive.

Calcium is likely to be the element that reacts with oxygen to give a compound with a high melting point and is soluble in water. Calcium oxide (CaO) is a compound with a high melting point and is also known as quicklime, which is soluble in water to form calcium hydroxide (Ca(OH)2). This compound is commonly used in various applications, such as in cement and agriculture. Therefore, calcium fits the given description.

When an iron nail is dipped in a copper sulfate solution, a chemical reaction takes place. The iron reacts with the copper sulfate to form iron sulfate and copper. The light green color observed in the solution is due to the formation of copper ions in the solution. Therefore, the correct answer is that the color of the solution turns to light green.

When calcium is treated with water, it reacts less violently with water and bubbles of hydrogen gas formed stick to the surface of calcium.

An electrolytic cell consists of a positively charged anode and a negatively charged cathode. In this cell, the anode is the electrode where oxidation occurs, resulting in the release of electrons and the production of positive ions. Conversely, the cathode is the electrode where reduction occurs, causing the acceptance of electrons and the formation of negative ions. Therefore, option (iii) and (iv) are correct as they correctly identify the charges of the anode and cathode in an electrolytic cell.

Aluminum (Al) is the most abundant metal in the earth's crust. It makes up about 8% of the crust by weight. This is because aluminum is a highly reactive metal and easily combines with oxygen to form aluminum oxide, which is a major component of many minerals found in the earth's crust. Additionally, aluminum is widely used in various industries due to its low density, high strength, and corrosion resistance.

AgNO3 solution and copper metal will give a displacement reaction. This is because copper is less reactive than silver, and silver ions in the AgNO3 solution will displace copper atoms from the copper metal, forming copper ions and silver metal.

An ionic compound is formed when there is a transfer of electrons between atoms, resulting in the formation of ions. In KCl and NaCl, there is a transfer of electrons from the metal (K or Na) to the non-metal (Cl), resulting in the formation of positive and negative ions. Therefore, (i) and (iv) are ionic compounds.

However, in HCl and CCl4, there is no transfer of electrons. HCl is a covalent compound where the electrons are shared between the hydrogen and chlorine atoms. CCl4 is also a covalent compound where the electrons are shared between the carbon and chlorine atoms. Therefore, (ii) and (iii) are not ionic compounds.

Aqua regia is one of the few substances that can dissolve gold (Au). The lack of reaction in test tubes A and B (which contain only concentrated HCl and HNO3, respectively) further supports that the metal is gold, as these acids alone are not sufficient to dissolve gold. Only the combination of HCl and HNO3 in aqua regia can achieve this.

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Steel is an alloy that contains non-metal as one of its constituents. It is primarily composed of iron, which is a metal, but it also contains carbon, which is a non-metal. The addition of carbon to iron gives steel its unique properties such as increased strength and hardness. Therefore, steel is an example of an alloy that combines both metal and non-metal elements.

Gold (Au) and Copper (Cu) are refined by electrolytic refining. In this process, impure metal is used as the anode and a pure metal is used as the cathode. When electric current is passed through the electrolyte, metal ions from the anode migrate towards the cathode and get deposited, resulting in the purification of the metal. Since gold and copper are both metals, they can be refined using this method. Sodium (Na) and Potassium (K) are not refined by electrolytic refining.

Cu, Au, Zn, and Ag are all metals. However, Cu, Au, and Ag are typically found in their native state in nature, meaning they are found in their pure form without being chemically combined with other elements. On the other hand, Zn is usually found in nature as a compound, such as zinc oxide or zinc sulfide, rather than in its pure metallic form. Therefore, the correct answer is (iii) and (iv).