6th Grade Unit 6 Lessons 3 and 4 Atoms, Elements, Pure Substances and Mixtures

Atom

the basic building block of all matter; it is smallest amount of an element

Proton

A subatomic particle that has a positive charge and that is found in the nucleus of an atom

Neutron

A subatomic particle that has no charge and that is found in the nucleus of an atom

Electron

A subatomic particle that has a negative charge and is not found in the nucleus of the atom

Element

A pure substance made of only one kind of atom

Atomic number (of an element)

represents the the number of protons in the nucleus of an atom of that element

Chemical Symbol

one or two letters that represent an element; the first letter is always capitalized and the other letters are always lower case

physical property

a characteristic of a substance that can be observed or measured without changing the identity of the substance

chemical property

A characteristic of a substance that describes its ability to change into a new different substance with different properties

periodic table

A chart of the elements showing the repeating pattern of their properties

Nanotechnology

The science and technology of building microscopic devices, such as electronic circuits, machines, and ways to deliver medicine to cells, from single atoms and molecules

Compound

Is made up of different kinds of atoms chemically combined

Mixture

Contains a variety of elements and/or compounds NOT chemically joined, so the parts can be separated

Pure Substance

A substance that has definite physical and chemical properties, no matter how much of the substance there is, because it is made of only one type of particle

Heterogeneous

Mixture that does not have a uniform composition, meaning you can tell it is made of different materials

Homogeneous

Mixture that has substances evenly spread out, which makes it tough to tell that it is even a mixture just by looking at it

Element examples

Carbon, Oxygen, Hyrdogen

Compound examples

Sodium Chloride (salt), Carbon Dioxide, Water

Mixture examples

Tea and sugar, chocolate milk, sand and water

How many elements must be chemically combined to make a compound?

At least 2 elements

chemical bonds

attractive forces that hold atoms together in molecules

molecule

a particle that contains more than one atom joined together chemically

biochemicals

Organic compounds made by living things (examples include carbohydrates, lipids, proteins, and nucleic acids)

suspension

a heterogeneous mixture that separates into layers over time

colloid

heterogeneous mixture whose particles do not settle out

solution

A homogeneous mixture that forms when one substance dissolves another; examples include saltwater, tea, air, and steel