• Essential Question: How is matter made up?

Matter:•Anything that has mass and takes up space

Properties of matterPhysical properties:• These properties can be observed or studied without

changing the matter into something else.• Density, color, size, shape, melting point, boiling

point, freezing pointChemical properties• These properties can only be known when there is a

change to the matter- we will end up with something new

• Frequently the changes that occur are irreversible• Flammability, reactivity with other substances

Changes to matter• Physical changes do not change the

substance. Think about a piece of wood, a piece of paper, or a piece of metal.

• What can we do to them that does not result in something new?

• A chemical change will produce something new and different than what we started with.

• Paper, wood, metal, an egg…• What can we do to change these?

Substance• A substance, sometimes called a

pure substance, always has the exact same composition- everywhere in the universe.

• Elements, and compounds are substances

The Atom• An atom is the smallest piece of matter that

cannot be broken down into other substances without losing the properties of the matter.

• Elements (on the periodic table) are made up of a single type of atom.

• A chunk of gold has “uncountable numbers” of atoms (gabazillions!!!) together these atoms have the same density, the same color, same melting point, etc.

Compound• A compound is a combination of two or

more DIFFERENT atoms bonded together.• Examples: NaCl, C6H12O6 ,MgBr2 , CH3OH

• A molecule is a combination of two or more atoms covalently bonded together. The atoms may be of the same element or different elements.

• Examples: H2O, CO2, O2

Mixtures• A mixture is a combination of

substances. They do not have definite and constant composition.

• Two types of mixtures:

Homogeneous mixtures• A homogeneous mixture is a mixture

that has the same composition throughout.

• Examples: a beaker of salt water, a glass of Kool-aid, a balloon full of air,Ex: solutions

• More difficult to separate

Heterogeneous mixtures• A heterogeneous mixture is one that

does not have the same composition throughout.

• Examples: muddy water; a bucket of sand, salt, and nails; blood; milkEx: suspensions

• Easier to separate

Parts of an Atom• Nucleus–Proton –Neutron

• Electron

Nucleus2 parts

• Proton• + charge• 1.673 x 10-24 g• = Atomic mass unit 1 AMU

• Neutron• No charge• 1.675 x 10-24g• 1 AMU

Electron• Located outside the nucleus in the

electron cloud• - charge• 9.109 x 10 -28 g• 1/1678 AMU (~0 AMU)

The Periodic Table• Element name• Element symbol• Atomic number:– Tells how many protons are in the element

– this never changes– The number of electrons equals the

number of protons (in a neutral atom – we’ll talk about exceptions later)

–Which number is the atomic number?

Atomic Mass• Tells the mass of the element

Mass=number of protons + number of neutrons

• Which number is this?

Neutrons• Number of neutrons

= Atomic mass – atomic number• Big # – little # • Round the number to the nearest

whole number.

Exceptions

Isotope• An element with a different number

of neutrons• Protium H 1• Deuterium H 2• Tritium H 3• Carbon 12• Carbon 14

Ion• An element with a charge

• Has lost or gained electrons• Na+ or Na1+

• N3-