Phy Sci FINAL EXAM!!! Flashcards
A molecule of water (H2O) is made from _______ combining two hydrogen atoms and one oxygen atom
Chemically
The chemical elements that is most abundant in the human body
Oxygen
You put 1 spoonful of salt into 1 liter of water and stir
The resulting liquid is an example of a what
Heterogenous mixture
A material that can be represented by a chemical formula is
An element
The chemical formula for water, H2O, means that each water molecule contains
Two hydrogen atoms and one oxygen atom
Lead has a density of 11.3 g/cm3 and a mass of 282.5g
What is its volume
25 cm3
What are potential signs of chemical change
Release of gas
Change of color
Production of gas
The smallest unit of an element that maintains the properties of that element
Atom
How many atoms are in a single molecule of Fe2O3
5
Is a mixture a pure substance
No
Is iron an element
Yes
A group of atoms that act as a unit
Molecule
What is the density of a sample of liquid that has a volume of 125mL and a mass of 200g
1.6 g/mL
A chemical property of copper is its
Reactivity
A physical property of gold is its
Density
The mass of a 20L sample of gas with a density if 0.04 mg/L is
0.8mg
Is “because it’s heavy” a reason to use aluminum foil in your kitchen
Nope
An object’s volume can be found by dividing its mass by its
Density
Is ability to rust a physical or chemical property
Chemical
What do the different substances in a mixture do
Keep their properties
Is boiling a potential sign of chemical change
Nope
How can a chemical change be reversed
By chemical changes
A chemical change occurs whenever
New substances form
Is dissolving a physical change
Yes
Is evaporating a physical change
Yes
Chemical changes can affect physical and chemical properties whereas physical changes can affect
Physical properties
Matter is defined as anything that
Has mass and takes up space
The smallest unit of a substance that behaves like the substance is a
Molecule
What is made up of at least 2 different types of atoms
Compound
Unlike a mixture, a pure substance has
A fixed composition
A substance has a mass of 360g and a volume of 7.5mL
What is its density
48 g/mL
Stainless steel has chemical properties such as
Resistance to rust
Digesting food is an example of
Chemical change
The science of what matter is made of and how it changes
Chemistry
A substance that cannot be broken down into simpler substances
Element
Knowing the chemical properties of a substance will tell you how the substance
Reacts with other substances
Is cooking an egg an example of a physical change
No
H2O
Water
Cu
Copper
C12H22O11
Table sugar
Fe2O3
Rust
Define chemical change
When the identity of the substance is changed
Temperature is a measure of the average ______ energy of the particles in the object
Kinetic
What determines the speed of the atoms and molecules of a particular substance
Size of atoms and molecules
Temperature of the substance
Archimedes’ principle states that the buoyant force on a(n) __________ is equal to the weight of the displaced volume of fluid
Object in the fluid
The resistance of a fluid to flow
Viscosity
The change of a substance from a solid directly to a gas
Sublimation
Evaporation refers to the change of state from a
Liquid to gas
The law a conservation of mass states that mass cannot be
Created or destroyed
Ice floats in water because it is
Less dense than water
Gay-Lussac’s law relates the temperature of a gas to its
Pressure
Pressure is calculated by dividing force by the _______ over which the force is exerted
Area
Buoyant force is the _____ force exerted on an object immersed or floating on a liquid
Upward
As the temperature of a fixed amount of gas at a constant volume decreases, it’s pressure
Decreases
As the volume of a fixed amount of gas at a constant temperature decreases, it’s pressure
Increases
The measure of the average kinetic energy of the particles in an object
Thermal energy
All matter is made of atoms and molecules that are
Always in motion
The process of a solid changing directly into a gas is called
Sublimation
According to the law of conservation of mass,
Total mass stays the same in changes of state
when ice melts to form liquid, energy is
Released
The temperature at which a substance changes from a liquid to a solid is the
Freezing point
The engine of a car left running for a long period of time becomes hot because
Energy is transferred from burning gasoline
A substance changes from a liquid to a gas during evaporation because
Energy is absorbed
What happens to the particles of a substance when it condenses
Particles slow down and clump together
The notion that an object floats if the buoyant force on the object is equal to the object’s weight was described by
Archimedes
Pascal’s principal states that a contained fluid exerts pressure
Equally in all directions
Force divided by the area over which the force is exerted
Pressure
The speed at which fluid flows through a pipe is influenced by the
Flow rate of the fluid
Viscosity of the fluid
Cross-sectional area of the the pipe
As the pressure of a moving liquid increases, it’s speed
Decreases
Bernoulli’s principle described the property of a
Fluid in motion
As the temperature of a gas at a constant volume decreases, it’s pressure
Increases
What law is illustrated by the equation P1V1 = P2V2
Boyle’s Law
Gases are unique in comparison to solids and liquids because they
Are easily compressible
As the pressure of a gas at a constant temperature decreases, it’s volume
Increases
What property is shared by solids, liquids, and gases
Their particles are in content motion
Why does the volume of a gas decrease when the pressure increases
Gas particles are pushed together when the pressure is increased
A measure of average kinetic energy of the particles in an object
Temperature
The process of a liquid becoming a solid is called
Freezing
A state of matter that is NOT a fluid
Solid
How does the density if an object that sinks into a fluid compare to the density of the fluid q
The object that sinks is more dense than the fluid
Unlike a gas, a plasma
Conducts electric current
Charles’s law related the volume of a gas to its
Temperature
When a fixed sample of has increases in temperature, it must also
Increase in pressure
The kinetic theory helps to explain the differences between
States of matter
A gas becomes a liquid through a process called
Condensation
Compared to less massive particles at the same temperature, more massive particles
Move more slowly
The force keeping am object floating on a liquid is called
Buoyant force
Boyle’s law relates the volume of a gas to its
Pressure
When a fixed sample of gas increases in volume, it must also
Decrease in pressure
Dalton’s atomic theory was accepted because
There was evidence to support it
Atoms have no electric charge because they
Have an equal number of electrons and protons
According to the new model of the atom, electrons behave like
Waves on a vibrating string
According to modern atomic theory, it is nearly impossible to determine an electron’s exact
Position
Valence electrons determine an atom’s
Chemical properties
A mole is an SI base unit that describes the
Volume of a substance
If the atomic mass of carbon is 12u, 1 mole of pure carbon will have a mass of
12g
You have 85.5g of fluorine, which has a molar mass of approximately 19g/mol
How many moles of fluorine do you have
4.5mol
Democritus’s original atomic theory was revised because it
Did not have a scientific basis
What did Dalton’s atomic theory state
Atoms cannot be divided
Atoms of an element are alike
Atoms of different elements form compounds
A subatomic particle that has a negative charge is called an
Electron
Who determined that atoms could be divided
Thomson
Thomson made his discovery about the atom during an experiment using
Cathode rays
Thomson is responsible for discovering that an atom contains
Electrons
What is an atom’s nucleus made of
Protons and neutrons
Whose atomic model showed negative electrons orbiting the positively charged nucleus
Rutherford
