Chemists use a classification system to describe the stuff around us. The classification system first categorizes a sample of stuff as being composed of a single pure substance or of a mixture of two or more substances. Pure substances can either be composed of elements (like the 118 that currently make up the Periodic Table) or of compounds. And mixtures of substances can be composed of elements, compounds, or both elements and compounds. These components or parts of a mixture could be homogeneous (the same throughout) or separated into distinctly different regions or layers and referred to as a heterogeneous mixture.
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Classification of Matter - help6
There are two questions in this Question Group. The questions are similar in terms of difficulty. This questions presents learners with 4 different formulas and 4 different classes of matter. Learners must match them up by tapping on them to select them and then tapping on the Check Match button. The order of the formulas and classes is randomized. A mis-matched pair restarts the gameand re-randomizes the order of the statements. The statements are ...
Here are the statements used in one of one the two versions:
Version 1:
Mixture of Two Compounds
Pure Substance of an Element
O3 + H2O
CO2 + NaF
Pure Substance of a Compound
CO2
Mixture of An Element and a Compound
Cu
Stuff ... the things around us ... more technically referred to as matter, is made of atoms. But when you are looking at such stuff, there may be just a single type of atom in it - like copper atoms. A copper wire is a pure substance made of the element copper.
Or the stuff could be composed of groups of atoms of different types bound together to form a compound such as water ... which we chemists (in our nerdier moments) call dihydrogen monoxide.
Or the stuff around you could be composed of a mixture of elements or a mixture of compounds or even a mixture of both elements and compounds. This is the case for the air around you. Air is a mixture of several gases, like nitrogen gas and oxygen gas and other gases that are present at smaller percentages.
When we think about stuff from a chemical perspective, one of the first questions we chemists ask is ... What is this sample of matter made of? And when we ask that question, we typically use a system of classification that is described in the graphic below. Study the graphic and use it to answer this question.
Or the stuff could be composed of groups of atoms of different types bound together to form a compound such as water ... which we chemists (in our nerdier moments) call dihydrogen monoxide.
Or the stuff around you could be composed of a mixture of elements or a mixture of compounds or even a mixture of both elements and compounds. This is the case for the air around you. Air is a mixture of several gases, like nitrogen gas and oxygen gas and other gases that are present at smaller percentages.
When we think about stuff from a chemical perspective, one of the first questions we chemists ask is ... What is this sample of matter made of? And when we ask that question, we typically use a system of classification that is described in the graphic below. Study the graphic and use it to answer this question.
