warm-up: 1. convert 14 km to meters 2. convert 455 ml to liters

Warm-Up: 1. Convert 14 km to meters2. Convert 455 ml to liters

Practice:1. 1285 ml to L2. 19.78 km to m3. 89234 m to km4. .00564 km to m5. 190 cm to m6. 2423.232 mm to m7. 1800 g to kg8. 5343 hg to g9. 4.545 L to ml10. 2 days to seconds

Notes:Matter

Matter is anything that has mass and takes up space.

An atom is the smallest particle into which an element can be divided and still be the same substance.

If you lined up 70 million atoms, they would stretch across your pencil eraser.

A piece of paper is 1 million atoms thick.

An atom’s nucleus is its center.

The nucleus contains protons and neutrons

The atom is mostly empty space. Think of a baseball inside of Turner Field.

The number of protons determines the element’s identity

Warm-Up: 1. What is the “building block of matter?”

2. The number of ______ in the ______gives each element its identity.

Number of protons

= Atomic Number

Electrons are negatively charged particles in the electron cloud

Electrons “orbit” in electron shells

Energy Level # of electrons1 22 83 184 32

The number of the period (row) an element is in, is the same as the number of shells it has

The first shell needs to be full before the second shell gets any electrons.

The last, or outer, shell is called the VALENCE SHELL.The electrons in the valence shell are called valence electrons

The number of valence electrons determines reactivity

Warm-Up:1. How many valence electrons does carbon have?2. How many valence electrons does sodium have?3. How many valence electrons does chlorine have?

Isotopes have different numbers of neutrons in the nucleus

Atomic Mass: Average Mass of all isotopes in nature of that element

Mass Number: Number of protons and neutrons in the atom

A covalent bond happens when atoms share electrons

Warm-Up:1. How many electrons can fill the first shell of an atom? How many can fill shells 2 & 3?2. What is the valence shell?3. Draw a oxygen atom

Molecules are made of multiple atoms chemically joined together.

Covalent bonds usually happen between nonmetals

An ionic bond happens when atoms gain or lose electrons

An ionic bond happens when atoms gain or lose electrons

When atoms join to form molecules, they create a new substance with unique properties

The new substance is a compound

Sugar: C12H22O11

Ammonia: NH4

Warm-Up: 1. When atoms chemically bond together, they create a ______.

2. Atomic Number = # of ______ in the nucleus of an atom.

3. Draw a nitrogen atom (with shells)

Warm-Up: 1. __________ is made of particles that have volume and mass.

2. Draw an oxygen atom.

3. How many valence electrons does oxygen have?