ATOMS! WHAT’S IN

THEM?

PARTS OF THE ATOM

ATOMS CONTAIN A NUCLEUS AND AN ELECTRON CLOUD.

NucleusElectron Cloud

NUCLEUS… WHAT’S IN IT?

THE NUCLEUS HAS THE PROTONS

& NEUTRONS

ELECTRON CLOUD…

WHAT’S IN IT?THE ELECTRONS!

HOW DO YOU KNOW?

HOW DO YOU KNOW HOW MANY PROTONS ARE IN AN ATOM?

PROTONS= THE ATOMIC NUMBER (FROM THE PERIODIC TABLE)

ATOMIC NUMBER

ATOMIC WEIGHT

LET’S CHECK…

HOW MANY PROTONS DOES CHLORINE HAVE?

CHLORINE HAS 17 PROTONS

HOW MANY PROTONS DOES ARSENIC HAVE?

ARSENIC HAS 33 PROTONS

HOW DO YOU KNOW?HOW DO YOU KNOW HOW

MANY ELECTRONS ARE IN AN ATOM?

ELECTRONS= THE ATOMIC NUMBER (SAME AS PROTONS!)

LET’S CHECK…HOW MANY ELECTRONS DOES CHLORINE HAVE?

CHLORINE HAS 17 ELECTRONS

HOW MANY ELECTRONS DOES CHROMIUM HAVE?

CHROMIUM HAS 24 ELECTRONS

HOW DO YOU KNOW?HOW DO YOU KNOW HOW

MANY NEUTRONS ARE IN AN ATOM?

NEUTRONS = ATOMIC WEIGHT – ATOMIC NUMBER

SODIUM HAS 12 NEUTRONS(23-11)

ATOMIC WEIGHT

LET’S CHECK…HOW MANY NEUTRONS DOES COBALT HAVE?

COBALT HAS 59-27 = 32 NEUTRONSHOW MANY NEUTRONS DOES LITHIUM HAVE?LITHIUM HAS 7-3 = 4 NEUTRONS

LET’S REVIEW…HOW MANY PROTONS DOES MERCURY HAVE?

MERCURY HAS 80 PROTONS

MERCURY HAS 201-80 = 121 NEUTRONS

HOW MANY ELECTRONS DOES MERCURY HAVE?

MERCURY HAS 80 ELECTRONS

HOW MANY NEUTRONS DOES MERCURY HAVE?

What is the purpose of protons?

The number of protons tells you the identity of the element.

For example… you know that something has 24 protons in the nucleus, that means it is CHROMIUM!

Remember, the protons are located in the nucleus.

Protons…The number of protons also tells you the properties of the element.

For example… because calcium has 20 protons, it is a white, malleable, shiny, metal element.

Finally, protons are part of the atomic weight (mass).

Protons…

Determines Identity?

Determines Properties?

Determines Atomic Weight?

Determines Charge?

Protons Yes Yes Yes No

Electrons

Neutrons

What is the purpose of electrons?

The number of electrons tells you how the atom will bond with other elements.

Remember, they are located in the electron cloud.

Electrons…

When an element bonds with another, it exchanges electrons.

(for example H2 + O2-> H2O)

When this atom exchanges electrons, it becomes charged. Then, it is called an ion.

Electrons…

Determines Identity?

Determines Properties?

Determines Atomic Weight?

Determines Charge?

Protons Yes Yes Yes No

Electrons No No No Yes

Neutrons

determine the CHARGE of an atom. (when it is ionic!)

What is the purpose of neutrons?

The number of neutrons tells you the isotope of the element.

For example… Carbon-12 = diamondsCarbon-13 = medicineCarbon-14 = fossil dating

Neutrons…

Determines Identity?

Determines Properties?

Determines Atomic Weight?

Determines Charge?

Protons Yes Yes Yes No

Electrons No No No Yes

Neutrons No No Yes No

And, neutrons are the other part of the atomic weight.

Remember, the neutrons are located in the nucleus.