Question

Which of the following describe physical properties and which describe chemical properties of the element sodium? Its density is greater than that of kerosene and less than that of water. It has a lower melting point than that of most metals. It is an excellent conductor of heat and electricity. It is soft and can be easily cut with a knife. Freshly cut sodium is shiny, but it rapidly tarnishes in contact with air. It reacts very vigorously with water to form hydrogen gas (H2) and sodium hydroxide (NaOH).

Answer 1

The properties of sodium can be classified as physical and chemical. Physical properties include its density, melting point, conductivity, softness, and its appearance that tarnishes when exposed to air. Sodium's rapid reaction with water and formation of hydrogen gas and sodium hydroxide is considered a chemical property.

Step-by-step explanation:

The properties of sodium can be categorized as physical properties and chemical properties. Physical properties are features that can be observed or measured without changing the substance's identity. Physical properties of sodium presented here include: its density being greater than kerosene but less than water, its low melting point compared to most metals, its excellent conduction of heat and electricity, and its softness allowing it to be easily cut with a knife. Sodium's shiny appearance which tarnishes when in contact with air also reflects a physical property.

On the other hand, chemical properties are characteristics that emerge during a chemical reaction, they describe the substance's ability to change into another substance. Sodium's vigorous reaction with water, where it forms hydrogen gas (H2) and sodium hydroxide (NaOH), is a demonstration of its chemical property.

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