HESI A2 Chemistry
Exam
2026
Questions and Answers
(A+ Grade Guarantee)
, HESI A2 Chemistry
Study online at https://quizlet.com/_2yr6ol
1. Acid 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
2. atom the basic building block of a molecule that contains a nucleus and orbits
3. atomic mass the average mass of each of that element's isotopes
4. atomic number the number of protons in the nucleus, and it defines an atom of a particular
element
5. base 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.
2026
, HESI A2 Chemistry
Study online at https://quizlet.com/_2yr6ol
6. basic unit of mea- standard unit of a system by which a quantity is accounted for and expressed
sure (grams, liters, or meters)
7. catalysts substances that accelerate a reaction by reducing the activation energy or the
amount of energy necessary for a reaction to occur
8. Celsius 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.
9. chemical equa- combination of elements or compounds called reactants responding to create a
tions product or end result. Equations are written in the following manner: reactants
---> products. The arrow can go the other way or both ways
10. combustion a self sustaining exothermic chemical reaction usually initiated by HEAT acting on
OXYGEN and a fuel compound such as hydrocarbons
2026
Exam
2026
Questions and Answers
(A+ Grade Guarantee)
, HESI A2 Chemistry
Study online at https://quizlet.com/_2yr6ol
1. Acid 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
2. atom the basic building block of a molecule that contains a nucleus and orbits
3. atomic mass the average mass of each of that element's isotopes
4. atomic number the number of protons in the nucleus, and it defines an atom of a particular
element
5. base 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.
2026
, HESI A2 Chemistry
Study online at https://quizlet.com/_2yr6ol
6. basic unit of mea- standard unit of a system by which a quantity is accounted for and expressed
sure (grams, liters, or meters)
7. catalysts substances that accelerate a reaction by reducing the activation energy or the
amount of energy necessary for a reaction to occur
8. Celsius 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.
9. chemical equa- combination of elements or compounds called reactants responding to create a
tions product or end result. Equations are written in the following manner: reactants
---> products. The arrow can go the other way or both ways
10. combustion a self sustaining exothermic chemical reaction usually initiated by HEAT acting on
OXYGEN and a fuel compound such as hydrocarbons
2026
