Chem fall exam
A bicycle has a speed of 6 m/s. What is its speed in km/h? (1 km=1000 m)
21.6 km/h
What is the definition of matter?
Anything that has mass and takes up space
John Dalton stated:
Atoms are tiny, invisible particles, Atoms of one element are all the same, Atoms of different elements are different, Compounds form by combining atoms
He developed the planetary model of the atom
Bohr
Which scientist developed the atomic theory
Dalton
What is the formula for Mass?
Density x Volume
A formula with the lowest whole # ratio of elements in a compound is called
Empirical Formula
Predict the product(s) of this reaction (Don't worry about balancing)Pb(NO3)2 + KI →
PbI2 + KNO3
Ernst Rutherford discovered which part of the atom through the use of gold foil?
Proton
Atoms are made up of three basic parts, which are -
Protons, neutrons, electrons
The scientist responsible for "discovering" the nucleus is:
Rutherford
3Ca + 2AlCl3 --> 3CaCl2 + 2Al
Single Displacement
When two or more parts are mixed together and chemically combine so that you cannot see the different parts (or different ingredients), it is called a ______________.
Solution
What is the smallest unit of matter in the world?
an atom
The symbol for a substance dissolved in solution is ______
aq
The smallest unit of a pure substance that has the properties of that substance
atom
A physical change...
changes the physical properties of an object, but does not create a new substance.
Cr2O3
chromium (III) oxide
A mixture contains cobalt metal, copper metal, and tin metal. This mixture is mixed with nickel nitrate. Which metals, if any, will react?
cobalt
I am 2 or more elements chemically bonded.
compound
What process takes place when a gas becomes a liquid?
condensation
Name the compound CuO
copper (II) oxide
A chemical change
creates a new substance and cannot be undone.
What is the name for P2O5?
diphosphorus pentoxide
What did Thomson discover?
electron
Where electrons are likely to be found as they travel around the nucleus
electron cloud
If an object has a density of .6 g/mL and you put it into water, will it sink or float?
float
What units are used to measure Density?
g/cm3
What state of matter has molecules that bounce around at high speeds and are not close together?
gas
What units are used to measure mass?
grams
M&Ms
heterogeneous
When a measurement is repeatable and consistent it is said to have...
high precision
air
homogeneous mixture
When is the prefix mono not used?
never on the first element
What will be the result of the following:Br2 + NaF ->
no reaction will occur
What are covalent compounds made up of?
nonmetals
Protons have this charge -
positive
A set of data are all close to each other, but they are not close to the actual value. This set of data can be described as...
precise
How do you calculate mass number?
protons + neutrons
The nucleus is made up of -
protons and neutrons
In covalent bonds elements ____________ electrons.
share
7.82 x 10-6 is an example of scientific notation. The exponent of -6 tells you your number will be very ________.
small
When using scientific notation, a negative exponent means ...
the standard number is less than one
Why do ice cubes float in a glass of water?
the water is more dense than the ice cubes
Rutherford's gold foil experiment provided evidence that...
there is a dense positively charged nucleus at the center of an atom.
Neutrons have this charge
neutral
Isotopes of an element have a different number of...
neutrons
Convert this number to standard notation: 1.4 x 10-2
0.014
The students measured length during a science experiement, they got 12 cm. But the actual measurement was 14.25 cm. What was the percent error?
15.79%
What is the molar mass of fluorine gas?(beware!)
38 g/mol
Bromine-80 has how many neutrons?
45
How many significant figures: 100.000 cL
6
Write 6,700 in scientific notation.
6.7 x 103
Convert this number into scientific notation: 0.068
6.8 x 10^-2
6 kg = _____ g
6000
Jack has a rock. The rock has a mass of 14g and a volume of 2cm3. What is the density of the rock?
7 g/cm3
Convert this number to standard notation: 7.1 x 104
71,000
Convert this number into scientific notation: 950,000
9.5 x 10^5
How close a measurement is to the true value is called..
Accuracy
What scientist is best known for his "Plum Pudding" model of the atom?
J.J Thompson
Aluminium is more reactive than ....
Lead and Iron
Predict the product(s) of this reaction (don't worry about balancing): Li + H2O →
LiOH + H2
What is the formula for Volume?
Mass/density
12 protons and 13 neutrons
Mg-25
Predict the product(s) of this reaction (don't worry about balancing): Mg + HCl →
MgCl2 + H2
What is the name for NI3?
Nitrogen Triiodide
A tiny but very dense, positively charged portion of the atom that holds most of the atomic mass
Nucleus
What do silver, platinum, and gold have in common?
They react very easily.
Unlike Ionic compounds, Covalent compounds require what when naming them?
a prefix
A set of data are not close to each other, but the average of the data is very close to the actual value. This set of data can be described as...
accurate
What state of matter has molecules spaced apart from one another and changes its shape depending on its container?
liquid
Name the following ionic compound: MgSO4
magnesium sulfate
The amount of matter something contains is its ______________.
mass
What two types of measurements make up DENSITY?
mass and volume
What is the formula for density?
mass/volume
Anything that has weight and takes up space is called
matter
When two or more things are mixed together and you can see the different parts or could easily take it apart, it is called a _______________.
mixture
When two or more atoms come together, they form a what?
molecule
Electrons have this charge -
negative
An atom's overall charge is ________.
neutral
