Exam 1 Flashcards
(106 cards)
Atomic Theory
- Everything is made of atoms
- Atoms are the smallest whole unit of am element
- Atoms combine with like and different atoms to form molecules
Chemical Reaction
- Chemicals interact to form different substances with different properties
- Reordering of atoms
Chemical Property
- describes a chemical change that a substance undergoes
- 2 types: intensive and extensive
Elements
- Substances that cannot be decomposed into simpler materials by chemical reactions
- Atoms all contain the same number of protons
Compound
- Substance formed from two or more different elements in which the elements are always combined in the same fixed proportions by mass
Pure Substances
- Element or compound
Mixture
- Substance with variable composition
- Homogenous or heterogenous
Homogenous
- Same properties throughout sample
- Solution
Heterogenous
- Two or more phases with different properties
- i.e. oil and vinegar
Solution
Homogenous mixture
Mixture vs. Compound
No chemical change in a mixture. Chemical change in a compound.
Law of Conservation of Mass
Mass is conserved in chemical reactions
Law of Definite Proportions
In a given chemical compound, elements always combine in the same proportion by mass
Dalton’s Atomic Theory (know gist, do not need to memorize)
- Matter is made of atoms
- Atoms are indestructible and do not break apart
- In pure element samples, atoms identical in mass and properties
- Atoms of different elements differ in mass/ properties
- When atoms of different elements combine to form compounds, new and more complex particles form. However, in a given compound the constituent atoms are always present in a fixed numerical ratio.
Law of Multiple Proportions
Small whole numbers in ratios of elements in compounds
Atomic Mass
- mass of a single atom
Atomic Weight
- Listed on the P.T.
- Weighted average of masses of naturally occurring isotopes
Subatomic Particles
The stuff that makes atoms…. protons, electrons, neutrons
Atomic Number
- The number of protons in an atom
- denoted by ‘Z’
Mass Number
#p+#n denoted by 'A'
Mass Number
#p+#n denoted by 'A'
Periods
- Rows of periodic table
Groups
- Columns of periodic table
- Numbered or roman-numeral-ed
Alkali Metals
- Group IA (1)
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