Chemistry Unit 1
Card Set Information
Chemistry Unit 1
study of the composition, structure, properties, and changes of matter
the composition of matter relates to...
the kinds of elements it contains
the structure of matter relates to...
the ways the atoms of these elements are arranged
any characteristic that gives a sample of matter its unique identity
entity composed of two or more atoms with the atoms attached to one another in a specific way
What are the three states of matter?
Gas, liquid, solid
elements and compounds
has a single kind of atom and is represented by a chemical symbol consisting of one or two letters
composed of two or more elements joined chemically
The law of constant composition AKA law of definite proportions
States that the elemental composition of a pure compound is always the same
Also called solutions; composition is uniform throughout; the different parts of the mixture are not visible
composition is not uniform, it varies from one part of the mixture to another; different parts of the mixture are visible
matter does not change its composition; changes of state
a substance is transformed into a chemically different substance
are independent of the amount of matter examined and are used to identify substances
Relate to the amount of substance present
indicates how closely different measurements of a quantity agree with one another
indicates how well a measurement agrees with the accepted or "true" value
Elements in a column
Elements in a horizontal row
Metallic elements (metals)
Comprise the majority of the elements, dominate the left side and the middle of the periodic table;
Physical properties- shiny, ductile, and malleable; solid at room temperature; good conductors of heat and electricity
Located on the upper right side; physical properties-dull, brittle, poor conductors; many are gases at room temperature; good insulators
elements that lie along the line that separates metals from nonmetals; are better conductors than nonmetals, but not as good as metals; used as semiconductors and insulators
Main group elements
AKA representative elements; represented by the letter A
represented by the letter B
What are two elements that are liquid at room temperature?
Bromine (nonmetal) and Mercury (metal)
What are the chemical properties of metals?
Atoms of metals lose electrons to form cations (positive ions)
What are the chemical properties of nonmetals?
Atoms gain electrons to form anions (negative ions) when reacting with metals; when reacting with nonmetals, they share electrons with other nonmetal atoms to form molecules (covalent compounds)
What are the 7 diatomic elements?
I, Br, Cl, F, O, N, H
I Bring Clay For Our New House
1 Megameter (Mm)= 1 X 10
SI preferred unit for length or distance
SI preferred unit for mass
SI preferred unit for time
second; s or sec
SI preferred unit for amount of substance
SI preferred unit for temperature
precision is good but accuracy is poor
How many nonzero numbers are significant in a measured number?
All of them:
38.15 has 4
0.54 has 2
122.55 has 5
When are zeros counted as significant numbers?
When they are sandwiched between two sig figs; 50.8 has 3; 0.702 has 3; 0.40505 has 5
When they follow a nonzero number and a decimal point is shown; 25,000. has 5; 200.0 has 4; 0.0460 has 3; 1.600 has 4
When are zeros NOT counted as significant figures?
When they come before nonzero digits in numbers smaller than one (leading); 0.008 has 1; 0.0156 has 3; 0.0042 has 2; 0.000262 has 3
When they follow nonzero numbers and act as placeholders (trailing); 25,000 has 2; 200 has 1; 48600 has 3; 25,005,000 has 5
Represent objects that are counted- 2 soccer balls, 4 pizzas
Are from numbers in a defined relationship- 1 foot = 12 inches, 1 meter = 100 cm
When multiplying or dividing measured numbers...
The final answer must have the same number of sig figs overall as the measurement with the FEWEST sig figs OVERALL
When adding or subtracting measured numbers...
The final answer must have the same number of DECIMAL PLACES as the measurement with the FEWEST DECIMAL PLACES
How many m = 1 km?
How many mm = 1 m?
How many mm = 1 cm?
How many mL = 1 L?
How many mL = 1 dL?
How many cm
= 1 mL?
How many g = 1 kg?
How many mg = 1 g?
How can a percentage be expressed as a ratio?
Same units on top and bottom and the 100 on top or bottom of the ratio
What is the density of water?
Density of the substance relative to (divided by) the density of water
What is the equation for density
What is the equation for mass?
M = D x V
What is the equation for volume?
What is the equation for Fahrenheit?
F = 9/5(C) + 32
What is the equation for Celcius?
C = 5/9(F - 32)
What is the equation for Kelvin?
K = C + 273