Chemistry Spring 2025 Semester Exam

How do you determine the number of neutrons in a neutral atom?

• Subtracting the mass number from the atomic number

• Adding the mass number and the atomic number

• Finding the average of the isotopes of the element

• By counting the atom's bonds

How do you determine the number of protons and electrons in an atom?

• By using the atomic number

• By using the atomic mass

• By using the mass number

• By counting the atom's bonds

How do you determine the number of valence electrons an atom has?

• By looking at the atom's group number in the periodic table

• By using the atomic number

• By using the mass number

• By using the family the element is in on the periodic table

What is the difference between atomic number, atomic mass, and mass number?

• Atomic number is the number of protons, atomic mass is the average mass of isotopes, and mass number is the sum of protons and neutrons

• Atomic number is the sum of protons and neutrons, atomic mass is the number of protons, and mass number is the average mass of isotopes

• Atomic number is the number of electrons, atomic mass is the sum of protons and neutrons, and mass number is the average mass of isotopes

• Atomic number is the average mass of isotopes, atomic mass is the number of electrons, and mass number is the sum of protons and neutrons

What is a mole?

• A unit that measures the amount of substance

• 6.02 x 10 to the 23rd power

• A unit for converting between particles of a substance and mass or volume

• all of the above

Why do atoms bond? What is a bond?

• Atoms bond to achieve stability; a bond is a force that holds atoms together

• Atoms bond to increase energy; a bond is a type of chemical reaction

• Atoms bond to change color; a bond is a measure of temperature

• Atoms bond to decrease mass; a bond is a unit of pressure

What is the charge of all ionic compounds? Why?

• Neutral, because the total positive and negative charges balance

• Positive, because they gain electrons

• Negative, because they lose electrons

• Variable, depending on the elements involved

Given a formula for an ionic compound, identify the charge of the transition metal. For example, what is the charge on copper in CuOH?

• +1

• +2

• +3

• +4

What does a balanced equation tell you about a chemical reaction?

• The speed of the reaction

• The energy change in the reaction

• The conservation of mass

• The color change in the reaction

The small number within the formula which tells the number of atoms in a molecule is called:

• Coefficient

• Subscript

• Mole

• Molar Mass