Unit 4 - Bonded Particles
- Electrical Nature of Matter
Particle representations of matter as pure substances and mixtures. Pure substances are further subdivided into elements and compounds
The particles that make up substances can be compounded from smaller
The fact that compounds have definite composition leads us to Dalton’s model of the atom. Next we find that these smaller particles (atoms) have the property of charge and some internal structure; we use the Thomson model of the atom to account for our observations.
Matter is composed or pure substances or mixtures of these pure substances.
The molecules of pure substances have definite composition and properties
whereas the composition and properties of mixtures are variable.
Molecules of pure substances can be broken down into simpler particles (atoms or molecules).
The energy required to separate the atoms in a compound is greater than that required to separate molecules during a phase change.
Two kinds of charge are observed to exist in atoms. The mobility of charge
within and between atoms suggests atoms are composed of smaller particles
with opposite charge properties. Charge plays a role in the attractive forces
that hold solids and liquids together and binds the atoms in molecules or
Molecular substances are composed of neutral molecules, whereas ionic substances are lattice-work structures of ions. These two kinds of substance have different physical properties.
Dr. Michael M. Krop High School
Unit 4 Materials
Worksheet 1 - Molecular Compounds
Worksheet 2 - Ionic Compounds
Worksheet 3 - Representing ions and empirical formulas
Worksheet 4 - More empirical formulas