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(3rd Quarter Exams): Ph. Science

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Chemichal changes can affect physical and chemichal properties whereas physical changes can affect what?
Physical properties
if the atomic mass of a carbon 12 u, 1 mole of pure carbon will have a mass of
12 grams
An elements atomic number is equal to its number of
Protons
Unlike the modern model of the atom, Bohr's model states that
electrons move in set paths around the nucleus of an atom
Democritus's original atomic theory was revised because it
did not have a scientific basis
How much effect do commonly found isotopes have on the average atomic mass of an element?
More than rarely found isotopes
Two different isotopes of an element have different
numbers of neutrons
The abillity of an object to float on a fluid is influenced by the

A. buoyant force of a fluid
B. Density of an object
C. Density of the fluid
D. All of the Above
D. All of the above
You have 85.5 grams of fluorine, which has a molar mass of approximately 19 g/mol. How many moles of fluorine do you have?
4.5 mol
A subatomic particle that has a negative charge is called a(n)
electron
Force divided by the area over which the force is exerted is the calculation for
Pressure
A measure of the resistance to flow of a fluid is
Viscosity
Upward force exerted on an object immersed or floating on a liquid is called
Buoyant force
Daltons atomic theory was accepted because
There was no evidence to support it
Who determined that atoms could be divided?
Thompson
Avogadro's number is defined as the number of particles in
One mole of a substance
Atoms have no electric charge because they
have an equal number of electrons and protons
a unified atomic mass unit is equal to
one-twelfth the mass of a carbon- 12 atom
A chemichal property of copper would be its what?
Reactivity
A physical property of gold would be what?
Density
An object's volume can be found by dividing its mass by its what?
Density
Pascal's principle states that a contained fluid exerts pressure ____________
equally in all directions
As the pressure of a moving liquid increases, its speed
Decreases
According to the new model of the atom, electrons behave like
Waves on a vibrating string
What happens when an electron gains energy?
it goes to an excited state
The different substances in a mixture do what?
Keep their properties
Which property of a substance is not affected by physical change?
Reactivity
Bernoulli's principle describes the property of a(n)
fluid in motion
Which of the following is not a potential sign of chemichal change?
Boiling
Which is not a fluid?
Air, Water, Carbon dioxide, or wood
Wood
According to Rutherford's model of the atom, electrons behave like
Planets orbiting the sun
According to Bohr's theory, an electron's path around the nucleus defines its
Energy level
An electron jumps to a new energy level when
The atom gains or loses energy
Helium is used in balloons because it is
lighter than air
The notion that an object floats if the buoyant force on the object is equal to the object's weight was described by ____________
Archimedes
Which of the following is not an orbital

A. s
B. d
C. p
D. x
D. X
Diamond is known for its
Hardness
a mole is an SI base unit that describe the
amount of a substance
An atom's mass number equals the number of
Protons plus the number of neutrons
A mole is an SI base unit that describes the
Volume of a substance
Molar mass is defined as
the mass in grams of one mole of a substance
Valence electrons determine an atom's
chemichal properties
Thompson is responsible for discovering that an atom contains
electrons
What is a unit or quantum of light?
Photon
What is found in the outer energy level of an atom
Valence electrons
Cathode rays
The number of energy levels filled in an atom is determined by
electrons
Where are electrons likely to be found in an atom?
Orbitals
What is an atoms nucleus made of?
Protons and neutrons
What is the mass of a 2.5 mol of Ca, which has a molar mass of 40 g/mol?
100.0 g Ca
In who's atomic model did negative electrons orbit the positively charged nucleus?
Rutherford's
Counting atoms
The speed at which fluid flows through a pipe is influenced by the

A. Flow rate of the fluid
B. Viscosity of the fluid
C. Cross-Sectional area of the pipe
D. All of the above
D. All of the above
How can a chemichal change be reversed?
by chemichal changes
Which tool is best for separating a mixture of sand and water?
A filteration system
According to the modern atomic theory, it is impossible to determine an electrons exact
Position
When will a chemichal change occur?
When new substances form
What are three physical changes?
Dissolving, Bending, and evaporating