Characteristics of relative and radiometric dating technologies
Each element has characteristic chemical properties. The periodic table, a systematic representation of known elements, is organized horizontally by increasing atomic number and vertically by families of elements with related chemical properties.
The development of the periodic table (which occurred well before atomic substructure was understood) was a major advance, as its patterns suggested and led to the identification of additional elements with particular properties.
The number of protons in the atomic nucleus (atomic number) is the defining characteristic of each element; different isotopes of the same element differ in the number of neutrons only.
Despite the immense variation and number of substances, there are only some 100 different stable elements.
The historical division between the two subjects of physics and chemistry is transcended in modern science, as the same physical principles are seen to apply from subatomic scales to the scale of the universe itself. C: Nuclear Processes Core Idea PS2: Motion and Stability: Forces and Interactions PS2. Chemical reactions, which underlie so many observed phenomena in living and nonliving systems alike, conserve the number of atoms of each type but change their arrangement into molecules.
The committee developed four core ideas in the physical sciences—three of which parallel those identified in previous documents, including the National Science Education Standards and Benchmarks for Science Literacy [1, 2].
The three core ideas are PS1: Matter and Its Interactions, PS2: Motion and Stability: Forces and Interactions, and PS3: Energy.
We also introduce a fourth core idea: PS4: Waves and Their Applications in Technologies for Information Transfer—which introduces students to the ways in which advances in the physical sciences during the 20th century underlie all sophisticated technologies available today.
Different materials with different properties are suited to different uses.
The ability to image and manipulate placement of individual atoms in tiny structures allows for the design of new types of materials with particular desired functionality (e.g., plastics, nanoparticles). Different kinds of matter exist (e.g., wood, metal, water), and many of them can be either solid or liquid, depending on temperature.