Matter – anything that has mass and volume How do we measure mass in lab? How do we measure...

Matter

Matter – anything that has mass and volume

How do we measure mass in lab? How do we measure volume in lab? What unit is used to measure mass? What units are used to measure volume?

Pure substance

Atom-smallest building unit of an element that has the same properties of the element.

Pure substance – particles all the same; element or compound

Elements

An element : 1. simplest pure substance 2. composes the Periodic Table 3. The smallest part of an element 4. Elements are written in symbols Fe Cu Ag Au or P K I (always written

in single or double letters; first letter always capitalized

Some common elements and uses

Pass out the periodic table and find these on your own table.

Cl –bleachHg-mercury (barometers)Ne –neon (lights)Ag- silver (jewelry)Au-gold (jewelry)Zr- Zirconium (fake jewelry) He – helium (balloons)

Compound

Compound – different types of elements chemically combined.

Examples: HCl NaCl KI Element symbols are always capitalized

so you can tell the difference between an element and a compound.

Atom

Atom –smallest unit of an element

Each atom of the same element is always identical

Atoms are symbolized by a capital letter or a capital letter and one lower case letter. See Periodic Table.

Molecule

Molecule –simplest unit of a compound; two atoms that are chemically combined

You can have a molecule of a compound or a molecule of an element

See the difference on the board Oxygen, nitrogen, salt, rust

Mixture

Mixture – two or more substance mixed together but not chemically combined

Mixtures do not have formulas because they are not combined in a definite proportion

Two Types of Mixtures

Homogeneous mixture – homo=same; geneous = throughout

A homogeneous mixture is the same throughout

Example : salt water; whipped cream; hand lotion

Solution

Solution is a type of homogeneous mixture formed when one substance dissolves in another

Particles cannot be seen

Example: Kool-aid; stainless steel; candy kiss; atmosphere of gases

Heterogeneous Mixture

Hetero = different geneous= throughout A heterogeneous mixture is different

throughout. Can usually see the particles Example: Trail mix; Lucky charms;

cinnamon and sugar; Chex mix

Types of heterogeneous mixtures

Suspension – particles settle out of solution

Example: pond water

Colloid- particles spread throughout liquid; particles are small and do not settle out quickly

Example: milk and gelatin (jello)

How are compounds classified?

1.pH– acidic, basic or neutral

Review the pH scale. What is an acid? Base? Neutral?

Bases are slippery and taste bitter. When mixing and acid and a base you

always get a salt and water produced.

2. Organic or inorganic- organic compounds contain hydrogen and carbon (come from living or once living things)

(Examples: foods; gasoline, synthetic goods)

Inorganic- come from non living things such as air, minerals, soil.

3. Role in the body – Biochemicals=organic compounds that

make up living things.

4 categories of biochemicals

1. carbohydrates – source of energy 2. Lipids- store excess energy and make

up cell membrane 3. Proteins – one of the most abundant

types of biochemicals; builds cells 4. Nucleic acids- DNA and RNA; genetic

information and used to build protein.