Chemistry Instructional Guide

Atoms and Elements

Chemistry

Quarter 1

HMHUnit 2

● Identifcation of an element by the number of protons ● The number of protons and neutrons in the nucleus before and after radioactive decay ● The identity of the emitted particles (i.e., alpha, beta - both electrons and positrons, and gamma) Interpreting Data Students use the analyzed data to make a claim that: ● The total number of neutrons plus protons is the same both before and after the nuclear processes ● The mode of decay (alpha, beta, or positron) can be predicted based on patterns in the overall size of the nucleus and the ratio of protons to neutrons Standard 1.3 What does it look like to demonstrate profciency on this standard? Representation Students clearly defne the system, including: ● Describing the radioactive isotopes and product isotopes ● Identifying the radiation (high energy particles) released and how they are measured Students identify and describe the rate of radioactive decay using mathematical representations of: ● The measurement of the ratio of radioactive isotopes to isotopes produced during radioactive decay at a given time Students support the claim that : ● The half-life of a radioactive isotope is independent of the amount or concentration of the unstable nucleus Mathematical modeling Students use mathematical relationships to: ● Create graphical or computational (such as a data table) representations ● Predict the amount of an unstable isotope at a given time Analysis Students use mathematical relationships to: ● Evaluate the limitations of dating of a material using radioactive isotopes ● Evaluate claims regarding the age of an object based on an isotopes rate of radioactive decay Standard 1.4 What does it look like to demonstrate profciency on this standard? Articulating the explanation of phenomena Students construct an explanation that includes: ● Identifcation of an element by the number of protons ● The number of protons and neutrons in the nucleus before and after the decay ● The scale of energy changes associated with nuclear processes, relative to the scale of energy changes associated with chemical processes Evidence Students identify and describe the evidence to construct the explanation, including: ● Heavy elements are formed in supernova; lighter elements are formed in stars