Exploring Atomic and Mass Numbers

The video tutorial explains the periodic table's atomic and mass numbers. The atomic number, denoted by Z, indicates the number of protons in an atom and is unique to each element. The mass number, denoted by A, represents the total number of protons and neutrons. The tutorial provides examples using hydrogen, oxygen, and lithium to demonstrate how to calculate the number of neutrons by subtracting the atomic number from the mass number.

What two key numbers are found in each element's box on the periodic table?

• Atomic number and electron number

• Mass number and neutron number

• Atomic number and mass number

• Proton number and electron number

What does the atomic number (symbol Z) represent?

• The number of neutrons in an atom

• The number of protons in an atom

• The number of electrons in an atom

• The total mass of an atom

Which element has an atomic number of 1?

• Hydrogen

• Lithium

• Oxygen

• Carbon

What does the mass number (symbol A) indicate?

• The total number of electrons in an atom

• The number of protons and electrons in an atom

• The number of neutrons and electrons in an atom

• The number of protons and neutrons in an atom

Why is the mass of electrons not considered in the mass number?

• Because electrons have a negative charge

• Because electrons are not present in all atoms

• Because electrons are too small to significantly affect the mass

• Because electrons are not part of the nucleus

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

• Add the atomic number to the mass number

• Divide the mass number by the atomic number

• Subtract the atomic number from the mass number

• Multiply the atomic number by the mass number

If an oxygen atom has a mass number of 16 and 8 protons, how many neutrons does it have?

• 12

• 10

• 8

• 6

Lithium has a mass number of 7 and 3 protons. How many neutrons does it have?

• 2

• 3

• 4

• 5

What is the relationship between the mass number and the atomic number?

• Mass number equals atomic number plus neutrons

• Mass number equals atomic number minus neutrons

• Mass number equals atomic number times neutrons

• Mass number equals atomic number divided by neutrons

What does the atomic number tell us about an atom?

• The number of neutrons

• The total mass

• The number of electrons

• The number of protons