Question

problem using a bunsen - burner, a set of known chemicals, and an unknown chemical compound, what is the identity of the unknown substance? background for thousands of years, people have known that burning certain chemicals produce colors specific to that chemical. until physicists and chemists started to learn about atoms and how they operate, they couldnt explain why the colors were emitted from the various chemicals. the law of conservation of energy states that energy cannot be created or destroyed, meaning that the total energy before any physical or chemical reaction must be equal to the total energy after it. we now know that each atoms electrons are able to absorb specific amounts of energy in order to jump to a higher location within the atom and in order to fall back down to its original location, it must release that exact same amount of energy in the form of a photon (particle of light). the longer the jump, the more energy is absorbed and released, which corresponds to different colors of light and even invisible versions of light. pre - lab questions 1. (2) what type of properties can be used to determine the identity of substances and what is the definition of this type of property? 2. (2) what type of properties cant help you determine the identity of a substance and what is the definition of this type of property? 3. (2) which of the two types of properties are the colors absorbed/emitted from atoms? what does this mean in terms of using the color to identify a substance?

Explanation:

1. Characteristic properties can be used to determine the identity of substances. These are properties that are unique to a particular substance and can be either physical (like melting - point, color) or chemical (like reactivity with other substances). For example, each element has a characteristic emission spectrum when heated, which is used in flame tests.
2. Non - characteristic properties cannot help determine the identity of a substance. These are properties that are common to many substances, such as mass or volume, which can vary depending on the amount of the substance present.
3. The colors absorbed/emitted from atoms are characteristic properties. Each element has a unique set of energy levels for its electrons. When electrons transition between these levels, they absorb or emit photons of specific energies (and thus specific colors). This unique "fingerprint" of colors can be used to identify the element in a substance.

Answer:

1. Characteristic properties; Properties unique to a substance that can be used for identification.
2. Non - characteristic properties; Properties common to many substances that do not aid in unique identification.
3. Characteristic properties; Each element has a unique color - emission/absorption pattern that can be used for identification.