Grade 5 Classroom Chemistry

Through research and scientific exploration students will learn about properties and interactions of safe to handle household liquids and solids.  Students test a variety of materials to see what happens when things are mixed together:  what dissolves, what reacts and what remains unaffected.  Students discover that when a solid material dissolves, it can be recovered as a crystal by evaporating the liquid.  They also learn that when two mixtures react to form a new material, the original materials cannot be recovered.  As an example of a chemical reaction, students learn to produce carbon dioxide gas and show that this gas differs from ordinary air.

All matter consists of particles.  We are familiar with the terms atom and molecule, the names given to particles of elements and compounds.  Another property of all matter on Earth, regardless of whether it is an element or a compound, is that it is in one of three states: solid, liquid or gas.*  What state a substance is in is dependent upon the amount of kinetic energy the particles have.  If the particles have low kinetic energy, their motion will be reduced to vibration in a fixed place, giving the substance a definite shape characterisitic of solids.  In solids, the strong forces between particles are weakened, so the particles will begin to move, sliding past each other, readily shifting around becoming a substance that can be poured and will take the shape of its container.  Now the substance is in the liquid state.  If a great deal of heat energy is added to the particles, they will begin pumping and pushing each other further and further apart so that there are spaces between them.  When the particles are moving about completely independent of each other, taking up the full volume of space provided them, the substance is said to be in the gaseous state.

Edmonton Public Schools, 1996

* There are more than three states of matter. However, the Grade 5 curriculum covers solids, liquids and gases.

Chemistry Vocabulary

Students: Please familiarize yourself with the following vocabulary words. A short quiz consisting of five words will be given Thursday January 19, 2012.

chemistry: The study of matter – its properties, composition, and changes.

matter:  Matter is everything that takes up space. All matter is made up of atoms.

solid:  A state of matter in which the substance has definite shape and volume.

liquid:  A state of matter in which the substance had definite volume but takes the shape of the container.

gas:  A state of matter in which the substance takes the shape of its container and is of low density compared to a solids and liquids. There is great expansion and contraction with changes in temperature and pressure.

atom:  The smallest part of an element that can exist and still retain the characteristics of that element.

element:  A pure substance in which all the atoms are the same.  Hydrogen is an element.

compound:  A pure substance containing two or more different elements united chemically.  Water is a compound consisting of hydrogen and oxygen in a ratio of 2:1.

physical properties:  Those properties that can be associated with a physical change in a substance. e.g. state of matter, density, color, boiling point, melting point, magnetic or conductor of electricity.

Chemistry Vocabulary

Adhesion:	The force of attraction between the surface of unlike bodies such as a solid and a liquid.
Atom:	The smallest part of an element that can exist and still retain the characteristics of that element.
Boil: .	To change from a liquid to a gaseous state. The boiling point of water is 100 degrees
Chemical:	A change in substances that have reacted chemically. The original substance is changed to a new substance. Change and cannot easily be recovered.
Chemical  Properties:	Describe how one substance will react with another. In a chemical reaction the products are very different from the reactants. The  physical properties of the products may be entirely different from the physical properties of the reactants.
Chemistry:	The study of matter - its properties, composition, and changes.
Cohesion:	The force of attraction between the particles (molecules) of a substance.
Compound:	A pure substance containing two or more elements united chemically. The molecules of the compound are all the same. Water is a compound consisting of hydrogen and oxygen in a ration of 2:1.
Decanting:	To pour off the top layer without disturbing the layers or the sediment below.
Density:	The amount of mass in a substance per unit of volume.
Distillation:	The process of vaporizing and then condensing a liquid.
Element	A pure substance in which all the atoms are the same. Hydrogen is an element.
Evaporation	A method of separating a solid from the solvent in which it is dissolved.  The solution is heated until all the liquid turns to vapor (evaporates) leaving the solid behind.
Filtering:	The process of passing a mixture of a liquid and a solid slowly through paper or other porous substance in order to remove the solid from the mixture.
Gas:	A state of matter in which the substance takes the shape of its container and is of low density compared to  solids and liquids. Great expansion and contraction with changes in temperature and pressure.
Heterogeneous  Mixture:	A mixture of varying composition; eg. a mixture of soil and sand may have more of one component in one sample than in another sample of the same size taken from elsewhere in the mixture.
Liquid:	A sate of matter in which the substance had definite volume but takes the shape of the container.
Mixture:	All of the atoms or molecules in a mixture may come from a variety of substances. A mixture is a number of pure substances brought together.  In most cases the pure substances can be isolated by relatively simple procedures.
Molecule:	The smallest part of a compound that can exist and still retain the properties of that compound.
Physical Change:	A change in a substance where no new substances are formed though the substance, itself, takes on different characteristics; eg. a solid becoming a liquid. Physical changes are reversible changes; eg. the substance can be returned to its original state or recovered from a mixture.
Physical properties:	Those properties that can be associated with a physical change in a substance. eg. state of matter, density, colour, boiling point, melting point, magnetic or conductor of electricity.
Product:	A substance obtained from one or more other substances as a result of a chemical reaction.
Pure substance	All of the atoms or molecules of the substance are the same. Gold is an element (a pure substance), all of the atoms in the sample of gold are the same. Water is a compound (a pure substance) all of the molecules of water in a pure sample are the same.
Reactant:	An element or compound that enters into a chemical reaction.
Saturated:	Referring to a solution that is not able to hold anymore solute at that temperature.
Solid:	A state of matter in which the substance has definite shape and volume.
Solute:	The substance that is dissolved in a solution.
Solution:	A homogeneous mixture in which the solute is uiformly distributed throughout the solvent.
Solvent:	The substance that does the dissolving in a solution.
Suspension:	A mixture in which very small particles of a solid remain suspended without dissolving.