Questions and Answers
Which of the following is a characteristic of non-metals?
Which change represents a chemical change?
Which of the following is true about metalloids?
What is the primary reason for mercury to be the only metal that is liquid at room temperature?
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Which of the following substances can conduct electricity?
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What happens when electric current passes through water?
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Which of the following non-metals is a poor conductor of heat and electricity?
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Which of the following elements is classified as a metalloid?
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What distinguishes the chemical properties of water from those of cooking oil?
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Which scientist first defined an element as a substance that cannot be broken down chemically?
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Which of the following is NOT a property typically associated with metals?
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What term refers to the chemical change that occurs when a substance reacts with oxygen?
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At room temperature, which state do most metals typically exist in?
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Which property of metals allows them to be drawn into wires?
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Which of the following best describes metalloids?
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Which characteristic is typical for non-metals compared to metals?
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What state are the majority of elements in at room temperature?
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Which of the following elements is a liquid at room temperature?
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When dilute sulphuric acid or hydrochloric acid is added to iron and sulphur, what is a possible observation?
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How many elements are known to exist as gaseous states at room temperature?
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Which two elements are specifically noted to be liquid just above room temperature?
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In a chemical context, what is a compound?
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Which group of elements has been found to show magnetic properties?
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Which of the following is true about the elements in liquid state?
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Study Notes
Changes in Matter
- Chemical Changes involve the alteration of chemical properties and result in new substances, such as rusting of an almirah, combustion, and the electrolysis of water into hydrogen and oxygen.
- Physical Changes include transformations that do not affect chemical composition, like melting butter, cutting trees, boiling water, and making a fruit salad.
Metals and Non-Metals
- Common metals include gold, silver, copper, iron, sodium, and potassium; these are typically solid and good conductors of heat and electricity.
- Mercury is unique as the only liquid metal at room temperature.
- Non-metals exhibit diverse colors, are poor conductors of heat and electricity, and are generally not lustrous, sonorous, or malleable. Examples of non-metals include hydrogen, oxygen, iodine, carbon, bromine, and chlorine.
- Metalloids possess intermediate properties between metals and non-metals, with examples like boron, silicon, and germanium.
Elements and Compounds
- Over 100 elements have been identified, with 92 occurring naturally. Most elements are solids at room temperature; only 11 are gases, and two (mercury and bromine) are liquids.
- Compounds consist of two or more elements chemically combined, differing in properties from their constituent elements.
Historical Context
- Robert Boyle first introduced the term "element" in 1661.
- Antoine Laurent Lavoisier defined an element in the 18th century as matter that cannot be further broken down by chemical reactions.
Key Properties of Metals
- Metals typically exhibit lustre, silvery-grey or golden-yellow colors, conductivity, ductility, malleability, and sonority.
Practical Experiments
- Conducting experiments to compare the properties of elements like iron and sulfur, while using acids to observe reactions, highlights changes and gas production, reinforcing the distinction between chemical and physical changes.
Miscellaneous
- Water and cooking oil demonstrate different chemical properties even when in liquid form; water extinguishes fire while oil burns, showcasing the variance in chemical behavior despite similar states.
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Description
Test your knowledge on the different types of changes in matter, including chemical and physical changes. Additionally, explore the properties and examples of metals, non-metals, and metalloids in this comprehensive quiz.
