問題一覧
1
What is chemistry?
the study of matter, its composition and changes that matter undergoes
2
What is matter?
is anything that occupies space and has mass
3
What is Microscopic perspective?
The macroscopic level of chemistry is related to the observable phenomena such as melting ice, burning a candle, and colour change.
4
Its is the smallest unit of a conpound or a substance that retains the chemical?
Molecule
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It contains atom of different elements and chemically combined together in a fixed ratio?
Compound
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is represented using pictorial, algebraic, physical, and computational shapes or using chemical formulas and structures.
Symbolic representation
7
isotopes
same atomic no. of protons but different atomic mass(neutrons)
8
happens when atoms lose of gain electrons
Ions
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Proper placement of the Equation
Coefficient, Reactants—Peoducts
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substances consumed?
Reactant
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Substances formed?
Product
12
Numbers before the formula?
Coefficient
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Has the same number of atoms of each element on both sides of the equation
Balance chemical equation
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a shorthand notation to describe a chemical reaction?
Chemical equation
15
It is the number of atoms of each element?
Substcipts
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What are the types of Chemical Equations?
Synthesis, Decomposition, Single Replacement, and Double Displacement
17
It is when one substance breaks down into two or more substances
Decomposition
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Its is the process of burning, the combination of a substance with oxygen to produce flame
Combustion
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Its is the sum of the atomic weight for the atoms in a chemical equation.
Formula Weight
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Formula weights are generally reported for what?
Ionic Compound
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_are written in parentheses to the right of each compound.
states of the reactants and products
22
1 Mole is equivalent to what?
6.022x10^23
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It is the “glue” that holds molecules together
Chemical Bonding
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Before 1985, what are the forms of carbon?
Diamond and Graphite
25
At the end of 1985, a new form of carbon was discovered at Rice University. What is that?
Buckminsterfullerenes
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Carbon can be produce by what?
Through Mining or Through laboratory synthesis
27
Diamonds electrical conductivity is?
Poor
28
Graphite electrical conductivity is?
Good
29
Graphene electrical conductivity is?
Very Good
30
Fullerene electrical conductivity is?
Semiconductor
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Reporting geometric arrangement
Crystalline
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Substance solidify into random arrangement
Amorphous
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No matter how we arrange the ball into the box, there will always be some gaps between them
Crystalline arrangement
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It is the percentage of space that is occupied in a given arrangement
Packing efficiency
35
A crystalline solid possess what?
a rigid and long-range order and solid, atoms, molecules or ions occupy specific predictable positions
36
Is the basic repeating structural unit of a crystalline solid
Unit cell
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Center of eight identical particles define the corners of the cube
Simple cubic unit cell
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Identical particles lie at each corner and in the center of the cube
Body centered
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identical particles lie at each corner and in the center of each face but not in the corner of the cube
face centered
40
What is the percent packing efficiency of a hexagonal crystal lattice?
74%
41
What is the percent packing efficiency of a simple cubic ?
52%
42
What is the percent packing efficiency of a Body centered ?
68%
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What is the percent packing efficiency of Face centered?
74%
44
Valence electrons of metal atoms are delocalized and more freely throughout the solid rather than being tied to any specific atom
Sea of electrons Model
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The valence shell of a metal contains closely spaced molecular orbitals
Bonding Theory
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What are the two types of Bond?
Valence and Conduction Bond
47
Are giants among molecules, constructed by the sequential stringing.
Polymers
48
smaller molecules is called?
monomer
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where single monomer unit is repeated
Block copolymer
50
Engineering material that is a copolymer is?
ABS- acrylonitrile, butadiene& styrene
51
Resulting material is both strong & flexible
Spandex
52
How many atoms lie nearest to a central atom of a body-centered cubic cell?
8
53
The following describes the addition polymerization, EXCEPT.
d. In addition polymerization, a molecule of water is eliminated as each monomer is added to the chain.
54
It is added to improve the flexibility of and strengthen the polymer.
Plasticizer
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It is added solely to change the color of the material and doesn't influence the underlying molecular
Pigments
56
Which of the following is true about nonmetals?
b. There is a quite large gap between the conduction band and the valence band.
57
A plastic that melts or deforms upon exposure to heat belongs to what category of polymer's physical?
d. Thermoplastic polymer
58
A type of copolymer in which monomers are arranged in a regular, alternating series.
alternating
59
Which of the following best describes the reason why diamond is the hardest substance?
b. Diamond consists of carbon atoms arranged in a three-dimensional octahedral lattice structure. Each carbon atom forms covalent bonds with four neighboring carbon atoms, resulting in a rigid, interconnected network.
60
Which of the following is true about metalloids?
d. There is a small gap between conduction and valence bands