HESI A2 Chemistry Exam Questions With Accurate Answers
Acid - accurate answers-a compound that is a hydrogen or proton donor. It is
corrosive to metals, changes blue litmus paper red, and becomes less acidic
when mixed with bases
atom - accurate answers-the basic building block of a molecule that contains a
nucleus and orbits
atomic mass - accurate answers-the average mass of each of that element's
isotopes
atomic number - accurate answers-the number of protons in the nucleus, and
it defines an atom of a particular element
base - accurate answers-a hydrogen or proton acceptor and generally has a
hydroxide (OH) group in the makeup of the molecule. Bases are also called
alkaline compounds and are substances that denature proteins, making them
feel very slick; they change red litmus paper blue and become less basic when
mixed with acids.
basic unit of measure - accurate answers-standard unit of a system by which a
quantity is accounted for and expressed (grams, liters, or meters)
catalysts - accurate answers-substances that accelerate a reaction by reducing
the activation energy or the amount of energy necessary for a reaction to
occur
Celsius - accurate answers-a temperature system used in most of the world
and by the scientific community; It has these characteristics:
zero degrees = freezing point of pure water at sea level
100 degrees = boiling point of pure water at sea level.
Most people have a body temperature of 37 degrees Celsius.
chemical equations - accurate answers-combination of elements or
compounds called reactants responding to create a product or end result.
Equations are written in the following manner: reactants ---> products. The
arrow can go the other way or both ways
, combustion - accurate answers-a self sustaining exothermic chemical reaction
usually initiated by HEAT acting on OXYGEN and a fuel compound such as
hydrocarbons
compound - accurate answers-the combination of two or more elements or
atoms
covalent bond - accurate answers-2 atoms share electrons, generally in pairs,
one from each atom
decomposition - accurate answers-a chemical reaction often described as the
opposite of synthesis because it is the breaking of a compound into its
component parts
deoxyribose - accurate answers-a sugar used in the formation of DNA
double replacement - accurate answers-a reaction that involves two ionic
compounds. The positive ion from one compound combines with the negative
ion of the other compound. The result is the two new ionic compounds that
have "switched partners"
electron clouds - accurate answers-the group of electrons revolving around
the nucleus of an atom; a cloudlike group of electrons
equilibrium - accurate answers-a state in which reactants are forming
products at the same rate that products are forming reactants
fahrenheit - accurate answers-a temperature measuring system used only in
the US, its territories, Belize, and Jamaica. It is rarely used for any scientific
measurements except for body temperature.
It has these characteristics:
0 degrees is the freezing point of sea water or heavy brine at sea level;
32 degrees F is the freezing point of pure water at sea level;
212 degrees F is the boiling point of pure water at sea level; most people have
a body temperature of 98.6 F
groups - accurate answers-elements that are placed together in columns in the
periodic table
Acid - accurate answers-a compound that is a hydrogen or proton donor. It is
corrosive to metals, changes blue litmus paper red, and becomes less acidic
when mixed with bases
atom - accurate answers-the basic building block of a molecule that contains a
nucleus and orbits
atomic mass - accurate answers-the average mass of each of that element's
isotopes
atomic number - accurate answers-the number of protons in the nucleus, and
it defines an atom of a particular element
base - accurate answers-a hydrogen or proton acceptor and generally has a
hydroxide (OH) group in the makeup of the molecule. Bases are also called
alkaline compounds and are substances that denature proteins, making them
feel very slick; they change red litmus paper blue and become less basic when
mixed with acids.
basic unit of measure - accurate answers-standard unit of a system by which a
quantity is accounted for and expressed (grams, liters, or meters)
catalysts - accurate answers-substances that accelerate a reaction by reducing
the activation energy or the amount of energy necessary for a reaction to
occur
Celsius - accurate answers-a temperature system used in most of the world
and by the scientific community; It has these characteristics:
zero degrees = freezing point of pure water at sea level
100 degrees = boiling point of pure water at sea level.
Most people have a body temperature of 37 degrees Celsius.
chemical equations - accurate answers-combination of elements or
compounds called reactants responding to create a product or end result.
Equations are written in the following manner: reactants ---> products. The
arrow can go the other way or both ways
, combustion - accurate answers-a self sustaining exothermic chemical reaction
usually initiated by HEAT acting on OXYGEN and a fuel compound such as
hydrocarbons
compound - accurate answers-the combination of two or more elements or
atoms
covalent bond - accurate answers-2 atoms share electrons, generally in pairs,
one from each atom
decomposition - accurate answers-a chemical reaction often described as the
opposite of synthesis because it is the breaking of a compound into its
component parts
deoxyribose - accurate answers-a sugar used in the formation of DNA
double replacement - accurate answers-a reaction that involves two ionic
compounds. The positive ion from one compound combines with the negative
ion of the other compound. The result is the two new ionic compounds that
have "switched partners"
electron clouds - accurate answers-the group of electrons revolving around
the nucleus of an atom; a cloudlike group of electrons
equilibrium - accurate answers-a state in which reactants are forming
products at the same rate that products are forming reactants
fahrenheit - accurate answers-a temperature measuring system used only in
the US, its territories, Belize, and Jamaica. It is rarely used for any scientific
measurements except for body temperature.
It has these characteristics:
0 degrees is the freezing point of sea water or heavy brine at sea level;
32 degrees F is the freezing point of pure water at sea level;
212 degrees F is the boiling point of pure water at sea level; most people have
a body temperature of 98.6 F
groups - accurate answers-elements that are placed together in columns in the
periodic table
