Understanding Mass Number Equation

This video tutorial explains how to use the mass number equation to determine the number of neutrons in isotopes. It begins with an introduction to the equation, which states that the mass number of an atom is the sum of its protons and neutrons. The tutorial then provides step-by-step examples using sodium and platinum isotopes, demonstrating how to rearrange the equation to solve for the number of neutrons by subtracting the atomic number from the mass number.

What does the mass number of an atom represent?

• The number of neutrons in the atom

• The number of protons in the atom

• The sum of protons and neutrons in the atom

• The number of electrons in the atom

How can you find the number of neutrons in an atom?

• By adding the atomic number to the mass number

• By subtracting the atomic number from the mass number

• By multiplying the atomic number by the mass number

• By dividing the mass number by the atomic number

What is the mass number of the sodium isotope discussed?

• 34

• 23

• 12

• 11

What is the atomic number of sodium?

• 34

• 23

• 12

• 11

How many neutrons are in the sodium isotope with a mass number of 23?

• 23

• 12

• 11

• 34

What is the chemical symbol for platinum?

• PN

• PT

• PM

• PL

What is the atomic number of platinum?

• 78

• 81

• 80

• 79

What is the mass number of the platinum isotope discussed?

• 23

• 78

• 195

• 117

How many neutrons are in the platinum isotope with a mass number of 195?

• 78

• 117

• 273

• 195