Question

part 3 - thinking with the periodic table

1. what do the elements that make colors in fireworks have in common about their location on the periodic table?
2. why do different elements give off different colors when heated?
3. which property of an element is most closely related to the firework color it produces?

a. atomic mass
b. valence electrons
c. number of protons
d. electron energy levels
application

1. if you were asked to design a purple firework, which two elements might you combine? why?
2. how does the periodic table act as a model to predict the properties of elements, even before we test them in fireworks?

Explanation:

Question 9

To determine the property related to firework color, we analyze each option:

• A. Atomic Mass: Atomic mass relates to the mass of an atom, not electron transitions (which produce color). Eliminate.
• B. Valence Electrons: While valence electrons are involved in bonding, the specific energy levels (not just valence) determine photon energy (color). Eliminate.
• C. Number of Protons: Protons define the element but do not directly control electron energy transitions (color production). Eliminate.
• D. Electron Energy Levels: When heated, electrons move between energy levels, emitting photons with energy (and color) determined by the energy difference between levels. This directly relates to firework color.

Purple light is a combination of red and blue (or high-energy blue/violet and lower-energy red). Elements producing red (e.g., Strontium, Sr) and blue (e.g., Copper, Cu) can be combined. When heated, Sr emits red photons, Cu emits blue photons; together, they create purple (red + blue = purple).

The Periodic Table organizes elements by atomic number (protons) and electron configuration. Elements in the same group (vertical column) have similar electron configurations (e.g., same number of valence electrons) and thus similar chemical/physical properties (including emission spectra). For example, alkali metals (Group 1) have similar reactivity, and transition metals (d - block) often produce vibrant colors. By analyzing an element’s group/period, we predict its electron energy levels, valence electrons, and thus its emission color (or other properties) without direct testing.

Answer:

D. Electron Energy Levels

Question 10