Chemistry Unit 2
Ni
Nickel
N
Nitrogen
NaCl: phenol (C6H6O): C2H6: . Ca3(PO4)2: formaldehyde (CH20): MgCO3: vitamin D2 (C27H40O): mercury sulfate (HgS): butane (C4H10): sand (SiO2): water (H2O):
inorganic organic organic inorganic organic inorganic organic inorganic organic inorganic inorganic
Elements listed in vertical columns of the periodic table: have similar chemical properties have similar physical properties are metals can combine with each other chemically
have similar chemical properties
metal
the group of elements that are good conductors of electricity and heat
nonmetal
the group of elements that are poor conductors of electricity and heat
C
Carbon
Au
Gold
physical change
a change in shape, size, or physical characteristics but remaining same substance
element
a primary substance that cannot be divided into separate substances
Fe
Iron
The usual units of density are:
g/cm3
Which of the following is not a phase change? melting of snow evaporation of water from the ocean condensation of water vapor to form clouds hydrogen and oxygen gas combining to form water vapor
hydrogen and oxygen gas combining to form water vapor
The rocks and minerals of the Earth consist of _________ compounds.
inorganic
NaCl: phenol (C6H6O): C2H6: Ca3(PO4)2: formaldehyde (CH20): MgCO3:
inorganic organic organic inorganic organic inorganic
A 56 g sample of peanut oil has a volume of 60.9 cm³. Calculate the density of the peanut oil. Remember to use the correct number of significant digits in your answer.
0.92 g/cm3
A sample has a mass of 35.4 g and a volume of 36.82 mL. What is the density of the sample?
0.961 g/mL
Helium has a density of 1.79 x 10-4 g/mL at standard temperature and pressure. A balloon has a volume of 6.3 liters. Calculate the mass of helium that it would take to fill the balloon.
1.1 g
Chlorophyll a is one of the green pigments found in plants. Chlorophyll a has the molecular formula /C55/H72/Mg/N4/O5/. How many atoms are in this molecule?
137
How many naturally occurring elements are there?
92
Al
Aluminum
U
Uranium
atom
smallest unit of an element
Which of the following was not a goal of the alchemists? to change lead into gold to discover a means to prolong life to discover new ways to use electricity to discover a universal cure for disease
to discover new ways to use electricity
compound
two or more elements joined together such that the elements have lost their individual identity
What does the term "compound" mean?
two or more elements joined together such that the elements have lost their individual identity in favor of a new set of properties
mixture
two or more substances dispersed in one another but each retaining their own identity
There are _____ naturally occurring elements.
92
He
Helium
O
Oxygen
Sn
Tin
Ba
Barium
Gelatin has a density of 1.27 g/cm3. If you have a blob of gelatin dessert that fills a 2.0-liter bottle, what is its mass?
2,500 g
Researchers have discovered that a moon rock brought back by the Apollo astronauts has a mass of 5.671 kg and a volume of 1,698 cm3. What is the density of the rock? Remember to use the correct number of significant digits in your answer.
3.340 g/cm3
A gold nugget has a volume of 20.0 cm3 and its density is 19.3 g/cm3. What is the mass of the gold nugget?
386 g
Ca
Calcium
Cl
Chlorine
Cu
Copper
All organic compounds are found in living organisms.
False
Density is inversely proportional to pressure.
False
Plastic products are made from inorganic compounds.
False
The Mohs hardness scale increases linearly from 1 to 10.
False
The density of a gas cannot be measured.
False
The physical properties of a compound are similar to those of its elements.
False
H
Hydrogen
Why does a weather balloon filled with Helium rise?
Its density is less than air.
Why does ice float after it crystallizes?
Its density is less than water.
Mg
Magnesium
Mn
Manganese
The name of the commonly used hardness scale is:
Mohs
Plants make glucose by a chemical process called:
Photosynthesis
grinding glass: rusting of iron: burning a candle: sanding wood:
Physical Chemical Chemical Physical
melting ice: souring of milk: digesting food: evaporating water:
Physical Chemical Chemical Physical
K
Potassium
All atoms of the same element have the same number of:
Protons
Ag
Silver
The softest and hardest minerals are:
Talc, diamond
metals
good conductors of electricity
Diamond will scratch quartz.
True
Hardness and density are physical properties.
True
Hardness is a physical property.
True
Hardness may be defined as the resistance of a material to scratching.
True
Iron filings can be separated from a mixture with sulfur by using a magnet.
True
Platinum will scratch gold.
True
The various components of a mixture do not combine chemically.
True
Unknown compounds can usually be identified based solely on their physical properties.
True
The smallest unit that can exist as an element and still have the properties of that element is a(n):
atom
Zn
Zinc
phase change
a change from one state of matter to another
alloy
a homogeneous mixture of elements with metals to form metallic solids
solution
a homogeneous mixture, usually a liquid with some substance dissolved in it
Law of Constant Composition
a pure compound consists of exactly the same elements in the exact same ratios by mass
Which has the greater density? air at sea level air at 20km altitude
air at sea level
alchemy
an ancient study or art which attempted to combine science and philosophy to solve worldly problems
Ar
argon
For each item, choose whether the change is a physical change or a chemical change. exploding firecracker: mowing grass: breaking a window: spreading butter on toast: burning wood in a fireplace: acid rain corroding gravestones:
chemical physical physical physical chemical chemical
compound
chemical combination of elements
heterogeneous
composed of dissimilar parts which can be separated easily
element
consists of only one substance
Which of the following physical properties would tell you about an element's mass per unit volume ratio? hardness boiling point crystalline shape density all of the above
density
The process of passing electricity through water to chemically separate it into hydrogen and oxygen is called what?
electrolysis
A substance which is made up of identical atoms is a(n):
element
An atom: is the smallest whole unit of matter can form one or more elements is the smallest whole unit of matter with the properties of a specific element all of the above
is the smallest whole unit of matter with the properties of a specific element
As a substance changes phase from gas to liquid to solid:
its density generally increases
Pb
lead
Using your knowledge of symbols, determine which compound listed must contain both copper and oxygen. glucose, C6H12O6 chalcopyrite, CuFeS2 malachite, Cu2CO3(OH)2 calcite, CaCO3
malachite, Cu2CO3(OH)2
Which is the correct definition of density?
mass/density
Hg
mercury
Inorganic compounds which are found in the earth are called:
minerals
colloid
mixture in which the suspended particles are too small to be seen with the naked eye
suspension
mixture that separates into individual components with time
A classification of matter which stipulates that the compound must contain carbon is called
organic
All man-made and most carbon-based compounds are
organic
Alexandria
original site of alchemy
nonmetals
poor conductors of electricity
Hardness is indirectely related to: surface roughness strength of chemical bonds mass weight
strength of chemical bonds
Hardness is related to:
strength of chemical bonds
atom
the simplest unit of an element that still retains the properties of that element
chemical change
the starting materials completely lose their properties to form new substances