Atomic Number Mass Number And Isotopes In Chemistry

This video tutorial explains the concepts of atomic number, mass number, and electric charge. It uses examples from the periodic table, such as nitrogen and boron, to illustrate these concepts. The video also covers isotopes and their natural abundance, and provides practice problems to determine atomic number, mass number, net electric charge, and element identity. By the end, viewers will understand how to identify elements and calculate their properties using the periodic table.

What does the atomic number of an element represent?

• The atomic mass

• The number of protons

• The number of electrons

• The number of neutrons

Which of the following is true about isotopes?

• They have different numbers of protons

• They have the same mass number

• They have different numbers of neutrons

• They have different atomic numbers

Why is nitrogen-14 more abundant than nitrogen-15?

• It has fewer neutrons

• Its average atomic mass is closer to 14

• It has a higher atomic number

• It has more protons

What is the atomic number of boron?

• 15

• 11

• 5

• 10

If an atom has more electrons than protons, what is its charge?

• Positive

• Negative

• Neutral

• Zero

How do you determine the mass number of an element?

• By adding the number of protons and electrons

• By adding the number of protons and neutrons

• By subtracting the number of neutrons from electrons

• By subtracting the number of electrons from protons

What is the charge of a carbon atom with 6 protons and 6 electrons?

• Undefined

• Neutral

• Negative

• Positive

What is the identity of an element with 9 protons?

• Oxygen

• Nitrogen

• Fluorine

• Neon

An element has 13 protons and 10 electrons. What is its charge?

• 1+

• 3-

• 3+

• Neutral

Which element has an atomic number of 13?

• Magnesium

• Silicon

• Aluminum

• Phosphorus