What does this standard mean a child will know, understand, and be able to do?

6.P.2.1

• Recognize that there are more than 100 elements that combine in a multitude of ways that make up all of the living and nonliving things that we encounter

• Recognize that matter is composed of extremely small particles, too small to be seen with a classroom microscope, called atoms

• Atoms have all of the properties of matter in that all atoms have mass and occupy space

• Atoms are the smallest part of an element that has the chemical properties of the element

• Recognize that all atoms of the same element have the same properties; i.e. all iron atoms have the same mass and occupy the same amount of space; therefore, all matter made of iron has the same properties because of the iron atoms

• Also, iron atoms are different from carbon atoms or from any other element.

*NOTE: It is not essential for students to know the subatomic particles, for example, protons, neutrons, and electrons, which compose atoms. Atomic models do not need to be constructed or drawn.

6.P.2.2

• A substance in a: Solid phase is relatively rigid, has a definite volume and shape. The atoms that comprise a solid are packed close together and are not compressible. Because all solids have some thermal energy, its atoms do vibrate However, this movement is very small and very rapid, and cannot be observed under ordinary conditions

• When heat is added a solid can become a liquid. Liquids have a definite volume, but are able to change their shape by flowing. Liquids are similar to solids in that the particles touch. However the particles are able to move around

• Since particles are able to touch the densities of liquid will be close to that of a solid (water is a special exception)

• Since the liquid molecules can move they will take the shape of their container

• When heat is added a liquid can become a gas

• Gases have no definite volume or shape

• If unconstrained gases will spread out indefinitely

• If confined they will take the shape of their container. This is because gas particles have enough energy to overcome attractive forces

• Each of the particles are well separated resulting in a very low density

• Energy appears in different forms

• Heat energy is in the disorderly motion of molecules

• Atoms and molecules are perpetually in motion

• Increased temperature means greater average energy of motion so most substances expand when heated

• Most substances can exist as a solid, liquid or gas depending on temperature.

6.P.2.3

• A substance has characteristic properties such as density, a boiling point, melting point and solubility, all of which are independent of theamount of the substance and can be used to identify it. Physical properties involve things that can be measured without changing the chemical properties

• Matter can undergo physical changes which affect only physical properties

• Physical changes can involve changes in energy

• Solubility means the amount of solute that can be dissolved in a specific volume of solvent under certain conditions

• A solute’s solubility depends on the chemical nature of the solvent.

• Another important factor that influences solubility is the temperature of the system (the solute and the solvent)

• The most common solvent is water.

• Density is a property that describes the relationship between mass and volume.

• Investigate the physical properties of pure substances in terms of the unique temperatures at which each substance undergoes state changes

• Investigate that melting and freezing of a pure substance takes place at the same temperature and the boiling temperature is the same as the maximum condensing temperature

• The temperature remains constant during state changes of pure substances.