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
Whose Model determined that an atom’s positive charge is concentrated in the atom’s center
Rutherford
Avogadro’s number is useful for
Counting atoms
What is the mass of 2.5mol of Ca, which has a molar mass of 40g/mol
100.0g
What is the molar mass of an element with an average atomic mass of 9.012u
9.012 g
How much effect do commonly found isotopes have on the average atomic mass of an element
More than rarely found isotopes
An element’s atomic number is equal to its number of
Protons
Two different isotopes of an element have different
Numbers of neutrons
What is the mass number of an element that has 19 protons, 19 electrons, and 20 neutrons
39
A sodium atom, which has 11 electrons, has _____ electrons in its third energy level
1
Unlike the modern model of the atom, Bohr’s model states that
Electrons move in set paths around the nucleus of an atom
What are the 4 types of orbitals
S
D
P
F
An electron jumps to a new energy level when
The atom gains or loses energy
The number of energy levels filled in an atom is determined by
Electrons
How many electrons can each orbital hold
2
What charge does the nucleus of an atom have
Positive
According to Rutherford’s model of the atom, electrons behave like
Planets orbiting the sun
Oxygen’ atomic number is 8
This means that an oxygen atom has
Eight protons in its nucleus
You have 6.50 mol of chromium, which has a molar mass of approximately 52 g/mol
What is the mass in grams
338 g
Can electrons be found between energy levels
No
according to Bohr’s theory, an electron’s path around the nucleus defines its
Energy level
An atom’s mass number equals the number of
Protons plus the number of neutrons
A unified atomic mass unit is equal to
One-twelfth the mass of a carbon-12 atom
Avogadro’s number is defined as the number of particles in
One mole of a substance
Molar mass is defined as
The mass in grams of one mole of a substance
What is the mass in grams of 0.75 mol of sulfur, which has a molar mass of approximately 32 g/mol
24g
Found in the outer energy level of an atom
Valence electron
Where electrons are likely to be found in an atom
Orbital
Unit or quantum of light
Photon
This is what happens to an electron when it gains energy
Excited state
The order of elements in the periodic table is based on
The number of protons in the nucleus
Atoms of elements that are in the same group have the same number of
Valence electrons
Is sodium an alkali metal
Sodium
Semiconductors are elements that
Can conduct heat and electricity under certain conditions
Magnesium is located to the right of sodium because Magnesium has
More protons
As you move from left to right across the periodic table, elements
Become less metallic
How was Mendeleev’s periodic table arranged
By increasing atomic mass
What is Mendeleev known for
Publishing the first periodic table
When did Mendeleev create a new row in his periodic table
When chemical properties were repeated
Mendeleev left gaps in his periodic table because
No known elements fit there
Each column of the periodic table is
A group
The periodic law states that elements that have similar properties appear
At regular intervals
As you mice from up to down in a column of the periodic table, elements have
A higher atomic number
What is the location of elements in the periodic table related to
Electron arrangement
Elements that belong to the same group have the same number of
Valence electrons
Atoms that gain or lose electrons are called
Ions
Elements that have one valence electron tend to
Be highly reactive
Form ions
Become charged
The three main groups of elements are
Metals
Nonmetals
Semiconductors
Most elements are
Metals
Most elements on the left side of the periodic table are
Metals
Most nonmetals are
Brittle
Each element in an element family share the same
Number of valence electrons
Elements in an element family have similar
Chemical properties
How do you know they potassium, an alkali metal, is highly reactive
It has one valence electron
Are noble gases highly reactive
No
What do noble gases exist as
Single atoms
When can semiconductors conduct heat and electricity
Under some conditions
In his version of the periodic table, Mendeleev based his arrangement of the elements on an element’s
Atomic mass
The order of the elements in the modern periodic table is based on an element’s
Atomic number
Elements in a family often have a similar
Appearance
Where are the alkali metals located
The left-most column of the periodic table
Group 18 noble gases are relatively inert because
Their s and p orbitals are filled
Which element is a semiconductor
Silicon
Mendeleev studied the properties of elements and looked for
Patterns
As one moves from left to right across a period in the modern periodic table, elements become
Less metallic
A lithium ion is much less reactive than a lithium atom because
If has a filled outer s orbital
Metals tend to be
Good conductors of heat
Most halogens form compounds by
Gaining an electron to form a negative ion
Transition metals such as copper or tungsten form compounds by
Losing electrons to form positive ions
Silicon, a semiconductor, is often found in
Computers
What does the periodic law state
When elements are arranged by atomic number, elements with similar properties appear at regular intervals
What are nonmetals sometimes called because they do not conduct heat or electricity well
Insulators
What is another name for semiconductors
Metalloid a
Elements that have properties of both metals and nonmetals
Semiconductors
Reactive elements of group 17 that are poor conductors
Halogens
Highly reactive elements that belong to group 1
Alkali metals
Elements that belong to groups 3-12 and are somewhat reactive
Transition metals
Group 2 elements that have two valence electrons
Alkaline-earth metals
A compound differs from a mixture because it
Is held together by chemical bonds
Which compound is formed from a tight network of oppositely charged ions
Salt, NaCl
Often atoms join so that each atom will have
An outermost energy level that is full of electrons
The bonds that hold atoms together behave most like
Flexible springs
An ionic bond is a bond that forms between
Ions with opposite charges
In which type of bond do atoms share electrons
Covalent bonds
The anion formed from an oxygen atom is called
An oxide ion
Fe2O3 is names iron (III) oxide because it contains
Fe3+ ions
The name for the compound with the formula Cr2O3 would be written as
Chromium (III) oxide
A carbon atom can bond to four other atoms because it has
Four valence electrons
Alcohols are organic compounds that contain
Carbon, oxygen, and hydrogen
Which compounds have carbon-carbon double bonds
Alkenes
The “rings” of the DNA “ladder” are made up of
Paired monomers
Some polymers are elastic because they are made of
Tangles chains
Is salt a compound
Yes
Atoms and ions are held together by
Chemical bonds
Which of the following models could be used to compare the sizes of atoms in a molecule
Space-filling
There are strong bonds between the atoms in a piece of quartz
These bonds give quartz a
Hugh melting point
The attraction between molecules tends to be ______ the attraction between ions
Weaker than
Which molecules are most strongly attracted to one another
Water molecules
Sugar has a lower melting point than salt because sugar is made of
Molecules
A hydrogen bond between water molecules is which of the following when compared with the bonds within an individual water molecule
It is weaker
A compound with only two atoms would not have a
Bind angle
What model would show the bond angle
Ball-and-stick
Atoms sometimes form bonds to
Become more stable
Copper atoms are held together by ______ bonds
Metallic
Sodium has one electron in its outer shell and chlorine has seven electrons in its outer shell
The atoms will
Form an IONIC bond by TRANSFERRING their electrons
Oxygen atoms have 6 electrons in their outer shells
When two oxygen atoms bond, they will form a
COVALENT bond by SHARING their electrons
An ionic compound of calcium and chlorine would be named
Calcium chloride
A covalent compound made of one sulfur and two oxygen atoms would be named
Sulfur dioxide
An ionic compound made of copper (Cu2+) and oxygen would be named
Copper (II) oxide
The covalent compound N2O5 would be named
Dinitrogen pentoxide
Because the overall charge in a compound must be ________, the charge of iron in Fe2O3 can be calculated as 3+
0 (zero)
The chemical formula for an ionic compound of aluminum and chlorine is
AlCl3
The __________ formula of a compound is written in the simplest whole number ratio of atoms
Empirical
The formula C6H12O6 would be the what formula for glucose
Chemical and molecular
All organic compounds MUST contain the element
Carbon
The atoms in organic molecules are held together by
Covalent bones
The atoms of propane are held together by
Single bonds
Ethene differs from ethane in that it has a
Double bond
An alcohol must contain
-OH group
Polypropylene would be called a what because it contains a repeating pattern of propylenes
Polymer
What is a polymer that contains many different molecules of amino acids
Protein
What polymer determines your genetic makeup
DNA
A polymer of sugar molecules is called a
Carbohydrate
A compound is held together by
Chemical bonds
Each molecule of hydrochloric acid, HCl, contains one atom of hydrogen and
One atom of chlorine
In which substance do the molecules have the strongest attractions to one another
Sugar, a solid
In a metallic bond, the nucleus of one atom is attracted by a nearby atom’s
Electrons
The name for the compound with the formula CuBr2 would be written as
Copper (II) bromide
Formaldehyde, CH2O, and acetic acid, C2H4O2, have the same empirical formulas but different
Molecular formulas
The simplest organic compound is
Methane
Polymers are large organic molecules that are made of
Repeating units
A protein is a polymer that is made of
Amino acids
The forces that hold different atoms or ions together are
Chemical bonds
Each molecule of table sugar, C12H22O11, contains
12 atoms of carbon
22 atoms of hydrogen
11 atoms of oxygen
Gases take up a lot of space because gas molecules
Are not attracted to one another
Covalent bonds are formed between
Nonmetals atoms
Copper is a good conductor of electricity because it’s electrons
Can move from atom to atom
It is possible for different covalent compounds to have the same empirical formula because empirical formulas represent
A ratio of atoms in the compound
Alkenes are hydrocarbons that contain
Single covalent bonds only
What are the prefixes for ionic compounds
1 = mono 2 = di 3 = tri 4 = tetra 5 = penta 6 = hexa 7 = hepta 8 = octa 9 = nona 10 = deca
An oatmeal raisin cookie is an example of a
Heterogenous mixture
What determines whether a mixture is a suspension or a colloid
Size do particles
Chlorine, which is used in swimming pools to kill bacteria, is a
Solute
Pennies minted after 1984 contain 97.5% zinc and 2.5% copper
These coins are examples of
Alloys
Two liquids that form a heterogenous mixture are said to be
Immiscible
What is a method for separating a solution of muscible liquids
Distilling
Is gasoline a homogenous mixture
Yeah
Particles in a what can be separated by filtration
Suspension
The Tyndall effect is observed in
Collide
The electrons in a water molecule are gathered nearest to
The one oxygen atom
A molecule that has partially charged positive and negative areas is
Polar
Because many substances dissolve in water, water is referred to as
The universal solvent
Which is not a reason that a sugar crystal dissolves in water
Sugar decays
Which would not increase the rate at which a sugar cube dissolves
Reducing the amount of solvent
Dissolving sodium chloride in water will
Lower the freezing point of the solution
Which mixture is a good example of the way a solute can affect the freezing point and boiling point of a solution
Ethene glycol and water
What will not dissolve in water
Petroleum
What type of bonding occurs between two water molecules
Hydrogen bonding
Compounds that do not dissolve in water are usually
Nonpolar
