PS.2 Resources

PS.2 The student will investigate and understand that matter is composed of atoms. Key ideas include

a) our understanding of atoms has developed over time;

Central Idea: Atoms are composed of subatomic particles, each with their own location and characteristics. Atomic structure and properties are reflected in the periodic table.

· A series of contributions and discoveries has led to the development of the atomic theory. The atomic theory encapsulates our current understanding of the atom and its structure. The development of this theory illustrates the nature of science. The nature of science refers to the foundational concepts that govern the way scientists formulate explanations about the natural world. (a) Students are not responsible for the contributions of specific scientists.

· The electron cloud model best represents our current understanding of the atomic structure. The electron cloud model describes the atom as containing a dense nucleus of protons and neutrons surrounded by regions of space (clouds) where electrons are most likely to be found. (Note: the Bohr model is an inaccurate model and does not depict the three-dimensional nature of the atom; it implies that electrons are in static orbits.) (a) Students do not need to know electron configurations and the quantum mechanical model.

Matter consists of atoms held together by electromagnetic forces and exists as different substances which can be utilized based on their properties. Different substances with different properties are suited to different uses.

· Atoms are the basic building blocks of all matter. The properties of an atom are based on the number and arrangement of its parts. (a)

The atom consists of subatomic particles (protons, neutrons, and electrons) that differ in their location, charge, and relative mass. (a)

In order to meet this standard, it is expected that students will:

· provide examples to demonstrate how the development of atomic theory illustrates the nature of science. (a)

· construct and use models and simulations to represent the structure of atoms; evaluate the limitations of models used. (a)

· differentiate between scientific hypotheses, theories, and laws. (a)

PS.2 The student will investigate and understand that matter is composed of atoms. Key ideas include

b) the periodic table can be used to predict the chemical and physical properties of matter; and

● The organization of the periodic table can be used to predict the metallic character and tendency of main group elements to form ionic or covalent bonds. (b) Students do not need to know the properties of transition elements.

● Elements in the same vertical column or group of the periodic table contain the same number of electrons in their outer energy levels. These electrons are called valence electrons and give rise to similar chemical properties. (b) Students do not need to determine the number of valence electrons.

● Elements in the same row of the periodic table contain the same number of energy levels. (b) Students do not need to determine principle energy levels or electron configurations.

● interpret data in the periodic table to predict the chemical and physical properties of main group elements. (b)

PS.2 The student will investigate and understand that matter is composed of atoms. Key ideas include

c) the Kinetic Molecular Theory is used to predict and explain matter interactions.

The Kinetic Molecular Theory states that atoms and molecules are perpetually in motion and have kinetic energy.

● The relative amount of kinetic energy in a group of atoms or molecules is an important factor in determining its physical state. (c)

The changes of state that occur with variations in temperature or pressure can be described and predicted using the Kinetic Molecular Theory. (c)

construct and use models and simulations to represent and/or explain the atom and phases of matter; evaluate the limitations of models used when appropriate. (c)

develop a model that predicts and describes changes in particle motion, temperature, and state of a pure substance when thermal energy is added or removed. (c)

interpret diagrams representing different phases of matter. (c)

compose evidence-based conclusions, explanations, and arguments to identify changes in matter when thermal energy is added or taken away. (c)

Organization of the Periodic Table Notes/Activity with Answer Key

Dry Ice Sublimation Video