ATOMS

THEIR STRUCTURE AND THEPROPERTIES OF ELEMENTS

Miss Sofia Paz

MADE UP OF SUBATOMIC PARTICLES:

-PROTONS(+)

-NEUTRONS

-ELECTRONS(-)

First: Different elements or compounds have different properties:

States (luquid, solid, gas, plasma) this properties depend on the atoms of the

elements!

ATOM:Smallest possible piece of an element (without loosing their

properties)

Electrons (-)Protons (+)

Neutrons

The attraction of the

negatively charged

electrons and the

positively charged

protons keeps the

electrons close to

the nucleus.

How this subatomic particles form an ATOM?

-NUCLEOUS: NEUTRONS, PROTONS(+), -CLOUD OF ELECTRONS (-)

The attraction of the

negatively charged

electrons and the

positively charged

protons keeps the

electrons close to

the nucleus.

Electrons have less

mass than neutrons

and protons.

NOT constantConstant

ATOMIC NUMBER (Z)( NUMBER OF PROTONS)

# of # of

The number of protons is constant

in each element

The atom is

electrically neutral,

positive charges are

balanced with

the negative charges.

NO two elements have

the sameatomic number

the number of protons = the Atomic Number(Z)

ISOTOPES (when the number of neutrons change)

Why C14, C13, C12??? Is the NUCLEAR NUMBER: NUMBER OF PROTONS + NUMBER OF NEUTRONS

Alternate forms of elements (always same proton number butdifferent neutron number)

RADIOACTIVE ISOTOPE:

HOMEWORK FOR NEX CLASS! What are radioactive isotopes and What uses does they have?

ElECTRONS AND REACTIVITY:

Electrons properties: -amount of energy-how thigly they are held by protons

Depending on this properties electrons belong to differents energyleves:I energy level can hold up to 2 electronsII energy level can hold up to 8 electronsIII energy level can hold up to 18 electrons

HOW DOES ATOMS STRUCTURE DETERMINE HOW IT REACTS??

CONCEPT :CHEMICAL PROPERTIES ARE BASED ON STRUCTURE OF ATOMS

I energy level :2 electronsII energy level: 8 electronsIII energy level : 18 electrons

CONCEPT :CHEMICAL PROPERTIES ARE BASED ON STRUCTURE OF ATOMS

Element/

isotope

Atomic

Number

Protons Neutrons Total electrons

(same number

ofprotons+)

12C 6

14C

14N 7

16O 8

P 15 15

S 16 16

Just howsmall is an atom??

• http://www.youtube.com/watch?v=yQP4UJhNn0I

• DOGS TEACHING CHEMSITRY

• http://www.youtube.com/watch?v=addK0b2Isw8