Atomic Structure Basics

What is the smallest unit of an element?

• atom

• cell

• molecule

• compound

Who discovered the electron?

• Albert Einstein

• J.J. Thomson

• Marie Curie

• Isaac Newton

What is the charge of a proton?

• Zero

• Negative

• Neutral

• Positive

What is the charge of an electron?

• -1.6 x 10^-18 C

• -1.6 x 10^-21 C

• -1.6 x 10^-20 C

• -1.6 x 10^-19 C

What is the charge of a neutron?

• Negative

• Neutral

• Charged

• Positive

What is the atomic number of an element?

• Number of electrons

• Number of protons

• Number of neutrons

• Number of isotopes

What does the atomic number represent?

• Atomic mass

• Number of neutrons

• Number of electrons

• Number of protons

What is the mass number of an element?

• Total number of electrons + protons

• Total number of electrons

• Total number of protons + total number of neutrons

• Total number of isotopes

• Total number of protons

How is the mass number calculated?

• By dividing the number of protons by the number of neutrons.

• By multiplying the number of protons by the number of neutrons.

• By adding the number of protons and neutrons in an atom's nucleus.

• By subtracting the number of electrons from the number of protons.

What is an isotope?

• Atoms with different numbers of protons.

• Molecules with varying electron configurations.

• Different elements with the same number of neutrons.

• Atoms of the same element with different numbers of neutrons.