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18 Cards in this Set
- Front
- Back
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Matter |
anything that has substance and takes up space (includes what we see and touch & what we cannot see e.g. air) |
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Does everything in the universe have a chemical connection? |
Yes |
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Substance |
matter with a definite and constant composition and distinct properties (water ammonia, table sugar, gold, oxygen) |
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How are substances identified? |
By smell, taste, appeared, etc |
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Mixture |
a combination of two or more substances where the substances maintain their distinct properties (milk, air, soda, cement) |
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Do mixtures have constant compositions? |
No, because samples of air from two different cities would likely show differences due to pollution and altitude |
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Homogeneous Mixture |
the composition of the mixture is the same throughout ( sugar dissolved in water) |
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Heterogeneous Mixture |
the composition of the mixture is not the same throughout (sand mixed with iron shavings) |
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Can mixtures be combined and then separated? |
Yes, both homogeneous and heterogeneous mixtures can be combined and then separated by physical means into the original pure components without changing the identities of the original components. |
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Element |
a substance that is unable to be separated into a simpler substance by chemical means |
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How many elements exist and where are they found? |
118 exist. Most occur naturally on Earth, the others are made via nuclear processes |
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How are elements represented? |
By symbols, with the first letter always being capitalized (Au=gold) |
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Compound |
a substance composed of atoms of two or more elements chemically united in fixed proportions |
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Can compounds be separated? |
Compounds can only be separated by chemical means into the original pure elements. |
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Solid |
matter in which the molecules are neatly and tightly packed together with little ability to move around |
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Liquid |
matter in which the molecules are close together, but they are not as close together, allowing them to slide past one another |
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Gas |
matter in which molecules have large gaps in between them |
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Can the three states of matter be converted without changing the composition of the substance? |
Yes. For example ice can be heated to the melting point, where it turns into water. Water can be heated to the boiling point, where it evaporates into water vapor. The water vapor gas can be cooled to turn it into water. Further cooling will freeze the water into ice again. |
