Module 1 Hierarchy of Matter and Separation Methods Unit 1: Matter Module 1 Hierarchy of Matter and Separation Methods 1

What is matter? Matter is anything that takes up space and has mass. Mass is the amount of matter in an object. Mass is resistance to change in motion along a smooth and level surface. 2

Classification of Matter 3

Pure Substances Elements- simplest kind of matter Cannot be broken down All one kind of atom. Compounds are substances that can be broken down by chemical methods (reactions) When they are broken down, the pieces have completely different properties than the compound. Made of molecules- two or more atoms 4

Mixtures (made up of two or more substances) Heterogeneous- mixture is not the same from place to place. One material is suspended, not dissolved within another. Heterogeneous mixtures can be either colloids or suspensions depending on the size of the particles. Example: Chocolate chip cookie, gravel, soil. Homogeneous- same composition throughout because particles of one substance are dissolved in another. All solutions are homogeneous mixtures. Example: Kool-aid, air, salt water solution (NaCl + H2O). Note: Every substance keeps its properties. 5

Homogeneous vs. Heterogeneous Solution - A homogeneous mixture where particles of one substance are dissolved within another. Samples taken at any point in the mixture will contain the same proportions of the matter that is mixed. Salt water, lemonade, and metallic alloys are examples. Colloid - A heterogeneous mixture that has the appearance of being homogeneous, but where particles are large enough that they are dispersed and suspended within the mixture, but too small for sedimentation (settling). Fog, gelatin, and milk are examples.   Suspension - A heterogeneous mixture where particles are large enough for sedimentation (settling). Pond water, soot, paint, and dust are examples. 6

Compounds vs. Mixtures All matter has one chemical structure Matter has at least two pure substances Making a compound involves a chemical process of combining elements Making a mixture involves a physical process of combining elements and compounds Separating a compound into elements involves a chemical process Separating a mixture into pure substances involves one or more physical processes Has a definite proportion by mass The proportion of pure substances is variable 7

Types of Physical Separation Skimming – Using an instrument to remove floating material from a mixture Decanting – Pouring off liquid to separate it from solid material at the bottom of the container Filtering – Using a filter to separate material based on the size of particles Distillation – Using heat to remove liquid from a mixture leaving behind solid material (evaporation) or a liquid with a very different boiling point (fractional distillation) Magnetism – Using a magnet to separate magnetic substances from non-magnetic substances Centrifuging – Using rotational motion to separate substances by mass 8

Key Terms Accuracy-the degree of closeness of measurements of a quantity to that quantity’s true value Colloid-heterogeneous mixture with small particles that hang in the mixture Precision-the degree which repeated measurements show the same results. Suspension-heterogeneous mixture with large particles that settle to the bottom. Tyndall effect-light scattering by particles in a colloid