1. 1 Introduction to the Particulate Nature of Matter Flashcards
State what is meant by the term element.
An element is a substance made of atoms that all contain the same number of protons and cannot be split into anything simpler.
True or False?
Nitrogen is an element.
True.
Nitrogen is an element.
True or False?
Water is an element.
False.
Water is a compound composed of hydrogen and oxygen atoms chemically combined.
State what is meant by the term compound.
A compound consists of atoms of different elements chemically bonded together in a fixed ratio.
True or False?
Compounds can be separated into their elements by physical means.
False.
Compounds cannot be separated into their elements by physical means.
What is a mixture?
A mixture contains more than one element or compound in no fixed ratio, which are not chemically bonded.
What is the difference between a compound and a mixture?
A compound consists of two or more elements that are chemically combined, while a mixture consists of two or more substances that are not chemically combined.
True or False?
All substances can be classified as elements, compounds, or mixtures.
True.
All substances can be classified into one of these three types.
Classify the following as an element, compound or mixture:
Air
Ammonia, NH3
Chlorine, Cl2
Copper sulfate, CuSO4
The classifications of the following are:
Air = mixture
Ammonia, NH3 = compound
Chlorine, Cl2 = element
Copper sulfate, CuSO4 = compound
What is the difference between an element and a compound?
An element consists of only one element, while a compound consists of two or more elements that are chemically combined.
Is a copper wire an element or compound?
Copper wire is an element.
Why is copper sulfate not on the Periodic Table?
Copper sulfate is not in the Periodic Table because it is a compound / not an element.
Define the term homogeneous mixture.
A homogeneous mixture is a mixture with a uniform composition and properties throughout.
True or False?
Air is an example of a heterogeneous mixture.
False.
Air is an example of a homogeneous mixture.
A mixture that has a non-uniform composition and different properties throughout is called a __________ mixture.
A mixture that has a non-uniform composition and different properties throughout is called a heterogeneous mixture.
Is concrete an example of a heterogeneous or homogeneous mixture?
Concrete is an example of a heterogeneous mixture.
What does simple distillation separate?
Simple distillation is used to separate:
a liquid and soluble solid from a solution (e.g., water from a solution of salt water)
a pure liquid from a mixture of liquids
State what is meant by the term simple distillation.
Simple distillation is a technique used to separate a liquid from a solution (e.g., water from a salt solution) by boiling the solution and condensing the vapour.
What is fractional distillation?
Fractional distillation is a technique used to separate two or more liquids that have different boiling points from a mixture.
Which technique separates solutions with more than one type of dissolved solid (solute)?
The technique that separates solutions with more than one type of dissolved solid is chromatography.
What does filtration separate?
Filtration separates an undissolved solid from a mixture of solid and liquid.
What is crystallisation used for?
Crystallisation is used to separate a dissolved solid from a solution.
In terms of the solid (solute), what is important about the solvent used for recrystallisation?
It is important that the solid (solute) is more soluble in hot solvent than in cold.
What is paper chromatography used for?
Paper chromatography is used to separate substances that have different solubilities in a given solvent, such as identifying the components of a mixture.
