Understanding Atomic Structure and Isotopes

What are the three main subatomic particles in an atom?

• Protons, neutrons, and photons

• Protons, neutrons, and electrons

• Electrons, positrons, and neutrons

• Neutrons, electrons, and quarks

Which subatomic particle is positively charged?

• Neutron

• Electron

• Proton

• Positron

What defines an isotope of an element?

• Different number of protons

• Different number of electrons

• Different number of neutrons

• Different number of atoms

How is the relative atomic mass of an element calculated?

• By averaging the masses of all isotopes

• By adding the number of protons and neutrons

• By averaging the masses of isotopes weighted by their abundance

• By counting the number of electrons

Which of the following is the electron configuration for a neutral oxygen atom?

What is the maximum number of electrons that can occupy the second energy level?

• 2

• 8

• 18

• 32

What is the term for the outermost electrons involved in bonding?

• Core electrons

• Valence electrons

• Free electrons

• Bonding electrons

How many valence electrons does a chlorine atom have?

• 5

• 6

• 7

• 8

Which of the following elements has a full outer electron shell in its ground state?

• Helium

• Lithium

• Oxygen

• Carbon