THE UNITS OF CHEMISTRYBy Maya Seaforth

Matter

What is matter? Matter is objects that take up space

and everything around you is made up of matter.

States of Matter

Solid – Solid is one of the three classical states of matter. It is characterized by structural rigidity and resistance to changes of shape or volume. The particles stay tied together.

Liquid

Liquid – Liquid is a form of matter with a definite value but no fixed shape. Like a gas, liquid is able to flow and take the shape of a container. The particles have room to move around.

Gas

Gas – Near absolute zero, a substance exists as a solid. It boils into gas at it’s boiling point. The particles move around freely in the absence of an applied electric field.

Physical & Chemical Properties

Physical – are properties that do not change the chemical nature of matter.

Chemical – are properties that do change the chemical nature of matter.

The difference between chemical and physical properties are that they are both opposite from one another.

Physical & Chemical Changes Physical – A physical change does not produce

a new substance, the changes in state or phase are physical changes.

Example: Melting an ice cube, breaking a bottle, crushing a can, crumpling a paper, car crash.

Chemical – Chemical change produces a new substance.

Example of chemical changes include: combustion, cooking an egg, rusting an iron pan, mixing hydrochloric acid, and sodium hydroxide to make salt and water.

Atoms

What is an atom? An atom is a basic piece of matter.

An atom itself is made up of three tiny particles called subatomic particles; protons; neutrons; and electrons.

Element

What is an element? In chemistry, an element is a pure

substance that cannot be broken down into any simpler substance by chemical methods.

Example: Iron (Fe) Gold (Au), Hydrogen (H), Carbon (C), and Oxygen (O)

Compound

What is a compound? Compound are pure substances

made of atoms of two or more elements chemically combined in fixed ratios.

Example: Carbon Dioxide (Co2), Water (H2O), Hydrogen Peroxide (H2O2), Table Salt (NaCl), and Carbon Monoxide (Co)

What is a Periodic Table?

The periodic table is a tabular display of the chemical elements, organized on the basis of their properties.

How do you read/use the periodic table? Step 1 – The element symbol. Symbols are the

abbreviations of the elements name. Step 2 – The elements atomic number. It’s the

number of protons and atoms of the elements contained.

Step 3 – The elements name. Many tables will include the names to help those who do not remember.

Substance/Mixture

Mixture – Made of more than one kind of material

Substance – Made of one kind of material.

What is the difference between them?

A mixture can have more than one material and the substance can have only one material.

Heterogeneous & Homogenous Mixtures

What is the difference between them? A homogeneous mixture has the same uniform

appearance and composition throughout. Many homogeneous mixtures are commonly referred as solutions.A heterogeneous mixture consists of visibly different substances or phases. The three phases or states of matter are gas, liquid, and solid.

Example for heterogeneous – salad dressing, strawberry shortcake, fruit salad, and party mix chips.

Example of homogenous – juice, soda, milk, tea, and lemonade.

Solutions

What is a solution? A homogeneous mixture of two or more substances, which may be

solids, liquids, gases, or a combination of these. Solute - A substance dissolved in another substance, usually the

component of a solution present in the lesser amount. Solvent - A substance in which another substance is dissolved,

forming a solution. Examples: Solvent - Water

Solute - SugarSolution - Sugar water

Solvent - Milk (hot)Solute - Cocoa powderSolution - Hot Cocoa

Solvent - WaterSolute - Kool-Aid powderSolution - Kool-Aid

Solubility

The maximum quantity of a substance that may be dissolved in another. The maximum amount of solute that may be dissolved in a solvent.