Atoms and the Periodic Atoms and the Periodic TableTable

L.E.Q. What is matter?L.E.Q. What is matter?

AtomsAtoms

An atom is composed of ELECTRONS An atom is composed of ELECTRONS (negative charge) orbiting the outside of a (negative charge) orbiting the outside of a nucleus.nucleus.

The nucleus is mad up of PROTONS (positive The nucleus is mad up of PROTONS (positive charge) and NEUTRONS (neutral charge).charge) and NEUTRONS (neutral charge).

Electrons orbit the nucleus of an atom in an Electrons orbit the nucleus of an atom in an electron cloud.electron cloud.

Electron CloudsElectron Clouds

Electron clouds can be broken into 7 different Electron clouds can be broken into 7 different energy levels.energy levels.

Each energy level can only hold a specific Each energy level can only hold a specific number of electrons.number of electrons.

Each energy level must be filled before a Each energy level must be filled before a higher energy level can have electrons.higher energy level can have electrons.

Electron CloudElectron Cloud

P N2e8e

8e18e

18e

32e

32e

Reading Information on Periodic Reading Information on Periodic Table Table

6

C

Carbon12.011

Electron Configuration

Atomic Number

Symbol

Name

Average Atomic Mass

*Memorize*Atomic # = # of protons in the nucleus

Atomic mass = # of protons + # of neutrons

# of neutrons= Atomic mass-atomic number (# of protons)

# of protons = # of electrons

Electron Configuration = # of electrons in outer most energy level (shell).

Why is the mass of carbon a decimal?

16

6A

PracticePractice

3

Li

Lithium6.941

What is the atomic number of Li?How may electrons are in Li?What is the mass number?How many neutrons are in Li?How many electrons are in Li’s outer shell? Draw a Lithium Atom

Look at the periodic table in your notes:

What is the name of an element that has 47 protons?

1

1A

Lithium AtomLithium Atom

Lithium has 3 protons and 3 electronsLithium has 3 protons and 3 electrons Atomic Mass is 6.941, round to the nearest Atomic Mass is 6.941, round to the nearest

whole number (7)whole number (7) Neutrons = Atomic Mass (7)-Atomic Number (3). Neutrons = Atomic Mass (7)-Atomic Number (3).

There are 4 neutrons in a Lithium AtomThere are 4 neutrons in a Lithium Atom

+o+oo+o

eee