The question asks for the term that describes the invisible water present in the air in the form of vapor. We need to identify the correct meteorological term from the given options.
C) Humidity — Humidity is the general term used to describe the amount of water vapor in the air. Water vapor is an invisible gas, and its presence in the atmosphere is what we refer to as humidity.
The question asks to identify the gas in the air that is essential for supporting combustion (burning). This requires knowledge of the basic chemical requirements for a combustion reaction.
Correct Option: A) Oxygen is an essential component for combustion. It acts as the oxidizer, reacting with the fuel to produce heat and light.
The question asks why a burning candle extinguishes when covered by an inverted glass jar. This phenomenon is related to the requirements for combustion. Combustion, or burning, is a chemical process that requires a fuel, an ignition source, and an oxidizer (typically oxygen).
A) The oxygen inside the jar gets used up during burning. This is the primary reason. Combustion is an oxidation reaction, and oxygen is essential for it to occur. By covering the candle, the supply of fresh oxygen is cut off, and the existing oxygen is quickly consumed, leading to the flame's extinction.
The question asks for a simple test to detect carbon dioxide gas. This requires knowledge of the characteristic chemical properties and reactions of carbon dioxide.
Correct Option: D) It turns freshly prepared lime water milky.
This is the standard and most widely recognized simple test for carbon dioxide gas. The milky appearance is due to the formation of insoluble calcium carbonate.
The question describes a common experiment used to demonstrate the presence of carbon dioxide in exhaled air. The key is understanding the chemical reaction between carbon dioxide and limewater (calcium hydroxide solution).
Correct Option: A) Carbon dioxide. The milky appearance of limewater when exhaled air is passed through it is a classic test for the presence of carbon dioxide, due to the formation of insoluble calcium carbonate.
This question tests knowledge about the role of oxygen in combustion. Combustion, or burning, is a chemical process that requires a fuel and an oxidizer, typically oxygen. The rate and intensity of burning are directly related to the concentration of oxygen available.
Correct Option: B) Burn more vigorously and brightly