Atoms & Molecules

ATOMThe smallest particle into which an element may be divided and still be the same substance.

Matter

Anything that occupies space and have mass .Energy is NOT matter

Matter is divided into 4 components:

Elements Compounds Mixtures Solutions

ELEMENTAll elements are on the Periodic TableAll matter is made of an element or a combination of elementsHydrogen, Oxygen, Gold A substance that consists of only one kind of atom and that cannot be chemically separated into other substances.

Elements:Elements cannot be changed into simpler substances by any chemical process . Elements are made up of atoms .

Simplest kind of matter Simplest kind of matter Cannot be broken down into Cannot be broken down into

simpler simpler All one kind of atom. All one kind of atom. There are 109 of these known There are 109 of these known

to manto man

Elements:

Substances that can be broken Substances that can be broken down by chemical methods down by chemical methods

When they are broken down, When they are broken down, the pieces have completely the pieces have completely different properties than the different properties than the compound. compound. Made of molecules- two or Made of molecules- two or more atomsmore atoms .

Compounds:Compounds:

Compounds:They are pure substances put

together by chemically combining elements

Not all combinations of elements

are compounds though– some

can be mixtures!

So remember… ELEMENTS contain only one kind

of atom

There are 109 different kinds of elements

1-109 = atomic # of the elements.

Solutions:Solutions: Solutions - A special mixture formed

when one substance dissolves in another .

Solutions:Solutions: Solvent - The most abundant

substance in the solution .

Solute - The least abundant substance in the solution .

All solutions are not liquids : Air is a solution of gases . Steel is a solution of metals .

MIXTURE :MIXTURE : Homogeneous mixture Homogeneous mixture Mixed molecule by molecule SolutionsMixed molecule by molecule Solutions

Can occur between any state of Can occur between any state of matter. matter. Solid in liquid- Cool-aid Solid in liquid- Cool-aid Liquid in liquid- anti freeze Liquid in liquid- anti freeze Gas in gas- air Gas in gas- air Solid in solid - brass Solid in solid - brass Liquid in gas- water vapourLiquid in gas- water vapour

SolutionsSolutions Like all mixtures, they keep the Like all mixtures, they keep the

properties of the components. properties of the components. Can be separated by physical Can be separated by physical

means means Do not scatter light!Do not scatter light! Not easily separated- Not easily separated-

But can be separatedBut can be separated..

Two techniques for separating solutions:

#1. Evaporation: changing

from a liquid to vapor state– leaves behind

the other component.

#2. Distillation: Process used to

drive vapor from liquid by heating

Great for separating two or more liquids which have different boiling points.

MIXTURE Matter that can be

physically separated into component parts

It is two or more kinds of matter that have separate identities because of their different properties.

When different parts of a

mixture can no longer be

separated into simpler

substances, we call each

component a PURE SUBSTANCE

There are two types of mixtures: Heterogeneous-Heterogeneous-

mixture is not the same mixture is not the same from place to place. from place to place. Chocolate chip Chocolate chip

cookie, gravel, soil. cookie, gravel, soil.

Homogeneous-Homogeneous- same composition same composition throughout. throughout. Cool-aid, air. Cool-aid, air.

Mixtures:

Matter that consists of two or more substances mixed together: but not chemically combined or bonded.

Examples: concrete, Sea Water, a bag full of different colored marbles..

Types of matterTypes of matter Properties of Mixtures :

Each substance retains its own properties.

Substances can be present in any amount .

Substances can be separated by simplem physical means.

Which is it?Which is it?

Element

Which is it?Which is it?

COMPOUNDWater is a compound formed from two hydrogen atoms and one oxygen atom chemically combined. H20

Which is it?Which is it?

MIXTURE

Decide if the substance is an Element , compound , mixture or solution?

1. Water

2. Salt

3. Oxygen

4. Dirt

5. Air

1. Compound

2. Compound

3. Element

4. Mixture

5. Solution

Click Mouse button to see answers!

What about MOLECULES?

These are MULTI-ATOM

particles

They are the smallest particle of a substance that still retains the properties of that substance and is composed of 2 or more atoms.

MOLECULEParticle of matter that is made up of two or more atoms.

Particle Charge Location Mass

Proton + nucleus heavy

Neutron 0 nucleus heavy

Electron - energy levels very light

Atomic NumberThe number of protons in the nucleus

17

C lChlorine

35.453

Atomic Number: 17Number of Protons: 17Number of Electrons: 17Atomic Mass: 35Number of Neutrons: 18

17

ClChlorine

35.453

SUBMITTED BY - CHITRANSH SRIVASTAVA CLASS - 9TH A SUBJECT - SCIENCE SCHOOL - KENDRIYA VIDYALAYA NO. 2 SUBMITTED TO - MRS . SHOBHA JOSHI