Ch. 1 - Introduction to matter
Standards covered in this chapter
7.PS1.1 - Develop and use models to illustrate the structure of atoms, including the subatomic particles with their relative positions and charge.
7.PS1.2 - Compare and Contrast elemental molecules and compound molecules.
7.PS1.3 - Classify matter as pure substances or mixtures based on composition.
7.PS1.4 - Analyze and interpret chemical reactions to determine if the total number of atoms in the reactants and products support the Law of Conservation of Mass.
7.PS1.5 - Use the periodic table as a model to analyze and interpret evidence relating to physical and chemical properties to identify a sample of matter.
7.PS1.6 - Create and interpret models of substances whose atoms represent the states of matter with respect to temperature and pressure.
Some important vocabulary:
Matter - anything that has mass and takes up space.
Physical Property - a characteristic of a substance that can be observed without changing it into another substance.
Chemical Property - a characteristic of a substance that describes its ability to change into different substances.
Element - a substance that cannot be broken down into any other substances by chemical or physical means.
Atom - the basic particle from which all elements are made.
Chemical Bond - a force of attraction between two atoms.
Molecule - a group of two or more atoms held together by chemical bonds.
Compound - a substance made of two or more elements that are chemically combined in a set ratio.
Chemical Formula - shows the elements in the compound and the ratio of atoms.
Mixture - made of two or more substances that are together in the same place, but their atoms are not chemically bonded.
Summary:
Every form of matter has two kinds of properties -- physical properties and chemical properties. Scientists know that all matter in the Universe is made of more than 100 different substances, called elements. You can determine the density of a sample of matter by dividing its mass by its volume. Every chemical and physical change in matter includes a change in energy. A mixture can be heterogeneous or homogeneous.
Everything that has mass and takes up space is matter.
Density is a measure of the mass of material in a given volume.
