Atomic Theory & Structure

In Bohr's model of the atom, where are the electrons located?

• in the center of the atom

• in energy levels outside the nucleus

• spread throughout the atom, like a chocolate chip cookie

Which part(s) of Dalton's atomic theory are false? Check all that apply.

• Atoms are indivisible (cannot be divided).

• Atoms of different elements can chemically combine to form compounds.

• During chemical reactions, atoms are rearranged, but never created or destroyed.

• Atoms of the same element are identical.

Why is an atom considered electrically neutral?

• The number of protons equals the atomic number.

• The number of electrons equals the number of neutrons.

• The number of protons is the same as the number of electrons.

• The number of electrons equals the number of protons.

Based on the gold foil experiment, what did Rutherford conclude about the atom. Check all that apply.

• The electrons orbit in definite paths around the nucleus.

• The atom contains a central, positively charged nucleus.

• It is impossible to know an electron's location and its speed at the same time.

• The atom is mostly empty space.

JJ Thomson used his cathode ray tube experiments to discover --

• a negatively charged particle called an electron

• a positively charged particle called a proton

• alpha particles

• a neutral particle called a neutron

A subatomic particle with a neutral charge is called

• a proton

• an isotope

• an electron

• a neutron

__________ determine the chemical reactivity of an atom.

• Protons

• Electrons

• Isotopes

• Neutrons

An atom with the same atomic number but a different mass number is called

• an ion

• an isotope

• an element

__________ are used to identify the element.

• Electrons

• Periodic Table

• Protons

• Neutrons

If you change the number of neutrons, you change the __________.

• charge

• mass

• identity