Define
Chemistry (must say three points)
Study of the composition, structure, and properties of matter, the processes that matter undergoes, and the energy changes that accompany these processes.
Hydrogen is 99% 1H, 0.8% 2H, and 0.2% 3H. Calculate its average atomic mass.
1.21 amu
Name all six branches of chemistry
Organic, analytical, biochemistry, theoretical, inorganic, physical
What are the vertical columns on the periodic table called?
Group
Is burning a log a chemical change or a physical change?
chemical
4 states of matter
gas, liquid, solid, plasma
Iodine is 80% 127I, 17% 126I, and 3% 128I. Calculate the average atomic mass of iodine.
126.86 amu
A forensic scientist uses chemistry to find information at the scene of a crime.
analytical
Neutrons
Distinguish between metals, metalloids, and nonmetals.
Metal: good electrical and heat conductor.
Nonmetals: poor heat and electrical conductors.
Metalloids: have characteristics of both metal and nonmetals.
1. Homogenous and 2.Heterogeneous
1. mixtures that are uniform in composition and cannot be separated physically
2. mixtures that are not uniform in composition and can be separated physically
6. Calculate the atomic mass of lead. The four lead isotopes have atomic masses and relative abundances of 203.973 amu (1.4%), 205.974 amu (24.1%), 206.976 amu (22.1%) and 207.977 amu (52.4%).
207.217 amu
A scientist uses a computer model to see how an enzyme will function.
theoretical/biochemistry
Is sugar homogeneous or heterogeneous?
homogeneous
Is tearing a sheet of paper a chemical change or a physical change?
Physical change
1.Reactant and 2.Product
1. left of arrow. substance at the start of reaction.
2. right of arrow. substance at the end of reaction
Antimony has two naturally occurring isotopes. The mass of antimony-121 is 120.904 amu and the mass of antimony-123 is 122.904 amu. Using the average mass from the periodic table, calculate the abundance of each isotope.
123Sb = 42.8 %
An oil company scientist tries to design a better gasoline.
organic
Define and contrast “mixture”, “compound” and “pure substance”.
Compounds are pure substances because they have fixed ratios. Compounds are not mixtures. Mixtures are two things mixed together physically. Compounds are 2+ chemicals bonded together chemically.
Explain how the law of conservation of energy applies to changes in matter.
Matter is neither created nor destroyed except with nuclear power’s help. We can only rearrange matter and energy. Matter can change form through physical and chemical changes, but through any of these changes matter is conserved. The same amount of matter exists before and after the change—none is created or destroyed. This concept is called the Law of Conservation of Mass.
1.extensive and 2.intensive properties
1. depends on the amount of the matter that is present
2. doesn't
Gallium has two naturally occurring isotopes. The mass of gallium-69 is 68.9256 amu and it is 60.108% abundant. The mass of gallium-71 is 70.9247 amu and it is 39.892% abundant. Calculate the atomic mass of gallium.
69.7231 amu
An anthropologist tries to find out the nature of a substance in a mummy's wrap.
biochemistry/analytical
Is an element that is soft and easy to cut cleanly with a knife likely to be a metal or a nonmetal?
Metal
Construct a concept map that includes the following terms: atom, element, compound, pure substance, mixture, homogeneous, and heterogeneous.
(Draw on whiteboard)
Matter
1. pure substance 2. Mixture
1a. Compound 1b. element 2a. heterogeneous 2b. homogenous
1ab. atoms