Term
| Law of definite (or constant) composition: |
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Definition
| No matter the source, a particular compound is composed of the same elements in the same parts (fractions) by mass |
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Term
| Law of multiple proportions: |
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Definition
| If elements A and B react to form two compounds, the different masses of B that combine with a fixed mass of A can be expressed as a ratio of small whole numbers |
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Term
| Law of Mass conservation: |
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Definition
| The total mass of substance doesn't change during a chemical reaction |
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Term
| Dalton's Atomic Theory: Four Postulates |
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Definition
1. All matter consists of atoms
2. Atoms of one element cannot be converted into atoms of another
3. Atoms of an element are identical in mass and other properties and are different from atoms of any other element
4. Compounds result from the chemical combination of a specific ratio of atoms of different elements |
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Term
| Mass conservation concepts: |
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Definition
-Atoms cannot be created or destroyed.
or converted into other types of atoms
-Since every atom has a fixed mass, during a chemical reaction atoms are combined differently and therefore there is no mass change overall. |
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Term
| Definite composition: concept |
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Definition
-Atoms are combined in compounds in specific ratios
and each atom has a specific mass.
-Therefore each element has a fixed fraction of the total mass in a compound |
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Term
| Dalton: Multiple Proportions concepts: |
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Definition
-Atoms of an element have the same mass
and atoms are indivisible
-So when different number of atoms of elements combine, they must do so in ratios of small, whole numbers |
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Term
| Modern Reassessment of the atomic theory: |
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Definition
1. All matter is composed of atoms
2. Atoms of one element can't be converted into atoms of another element in a chemical reaction
3. All atoms of an element have the same number of protons and electrons, which determines the chemical behavior of the element.
4. compounds are formed by the chemical combination of two or more elements in specific ratios |
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Term
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Definition
| An element with a different number of neutrons, therefore it has a different mass number. A sample of the element is treated as though its atoms have an average mass. |
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Term
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Definition
the simplest type of substance with unique physical and chemical properties.
consists of only one type of atom. Can't be broken down into any simpler substance by physical or chemical means.
Assigned a unique atomic number equal to the number of protons in an atom of that element |
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Term
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Definition
| 1/12 the mass of a 12C atom |
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Term
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Definition
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Term
| Which columns are main group elements? |
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Definition
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Term
| Which columns are transition elements? |
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Definition
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Term
What are the following columns classified as?
1A
2A
7A
8A |
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Definition
1A-Alkali metals
2A-Earth Alkali metals
7A-Halogens
8A-Noble Gases |
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Term
| Characteristics of metals: |
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Definition
-Characteristic luster
-Good conductors of heat and electricity
-Solid at room temperature |
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Term
| Characteristics of nonmetals: |
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Definition
-Dull in appearance
-Poor conductors of heat and electricity |
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Term
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Definition
| Properties are a mix of other classes |
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Term
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Definition
-Groups of atoms chemically bonded together
-Covalently bound compounds which share electrons
-H represents a hydrogen atom
-H2 represents a hydrogen molecule |
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Term
| Describe NaCl in terms of compounds, elements, etc. |
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Definition
| Ionic compound made of two charged ions. |
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Term
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Definition
| an ionic compound. A mix of a metal and a non-metal |
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