ATOMS-ELEMENTS AND COMPOUNDS REVISION

ATOMS AND ELEMENTS

Define Particle, Atom, Element, Compounds and Periodic table.

Contents of Slide Presentation Intro Atoms & ElementsAtoms – What are atomsAbout an atomAtoms & Shells Subatomic ParticlesCompounds and Chemical ElementsQuick QuizAtomic NumberAtomic Number CalculationsMass Number CalculationsNeutral Atom

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ATOMS

What are ATOMS?Atoms are the basic building blocks or tiny

particles (whose size are hard to imagine or even comprehend) that makes up matter (everything) in the universe.

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ABOUT AN ATOM(SUBATOMIC PARTICLES)

Note keywords: Basic, building, blocks, particles, matter, microscopic (size is hard to imagine)

_

PROTONS

NEUTRONS

ELECTRONS

Think of the sun with the planets spinning around it -this is how best you can probably describe and understand what an atom is.

+ Charge

ChargeNeutral

Atomic Particles

NUCLEUS


ATOMS AND SHELLS

• Electrons stay in their shells as they revolve round the nucleus because a special force (electrostatic force) holds them there. Protons (+ve charge) and electrons (- ve charge) are attracted to each other.

SUBATOMIC PARTICLES - PROTONS, ELECTRONS and NEUTRONSSubatomic particles in all atoms are smaller than the atom itself.


SUBATOMIC PARTICLES(MEMORY TIPS)

• An easy way to remember this is

Proton and

Positive start with the letter ‘P’

• Neutrons have no electrical charge. • An easy way to remember this is

Neutron and no electrical charge start with the letter ‘N’

Orbiting or circling/moving around outside the nucleus are tiny little particles called electrons


Compounds & Chemical Elements

• What are chemical elements?• What are compounds?• How are chemical elements different from

compounds?• All materials or matter that is

composed of only one type of atom is called a chemical element or just an element.

• However, compounds are made when atoms of different elements are chemically joined or combined together. Squashed together in the middle of the atom are protons and neutrons

Copy right © Science-tutors Media 2008 Compilation by Ivan Ukiwah

Compounds & Chemical Elements Quick Quiz

Which of these is an element or a compound?A

BC

D

Compounds are atoms of different elements. Elements are composed of only one type of atom


ATOMIC NUMBER

• What is an atom's atomic number?• What is an atom's mass number?

• Atomic Number is a unique number that identifies how many protons are present in one atom of an element.

• In science it is defined more precisely as the number of protons in the nucleus of an atom determines an element's atomic number.


ATOMIC NUMBER

ATOMIC NUMBER = Number of Proton

Element Atomic Number Number of Proton

Oxygen 8

Chlorine 17

Sodium 11

Magnesium 12

Carbon 6

Complete the table below


MASS NUMBER

• What is an atom's mass number?• Protons and neutrons are heavy particles

which when added together make up an atom’s mass

• A knowledge of atomic mass essentially tells us how many of these protons and neutrons there are in any atom.

+X number of protons

Y number of Neutrons

=x + y = mass number

Mass number tells how many protons and neutrons are there in an atoms.


MASS NUMBER

Element Atomic Number Number of Mass Number

neutrons

Oxygen 8 16

Chlorine 17 18

Sodium 11 12

Magnesium 12 24

Carbon 6 12

Complete the table below

NEUTRAL ATOM

An atom is in balance or neutral, if it has the same number of protons and electrons.

Neutral Atom is when the No. of Protons = No. of Electrons

That means number of positive charges = The number of negative charges.

So they cancel out and become neutralCopy right © Science-tutors Media 2008 Compilation by Ivan Ukiwah

Neutral Atoms Or Charged Ions

Element No. of Protons

No. of Electrons

Neutral Ion

Atom (+ve or – ve)


ATOMS AND MOLECULES

Learning Outcomes• L Define chemical reaction, molecule, and

compound, and name the atoms reacting and molecule produced in a reaction.

• I Use these names to construct a word equation showing the reaction.

• H Create a model of a chemical reaction between atoms to form a molecule.

REACTION OF METALS IN AIR

Objectives

• Metals can be heated in air to show signs of chemical reaction.

• To understand how metal oxides are formed.

METAL OXIDE

• Outcomes

• L Describe how to make an oxide safely and use your observations to list the signs of a chemical reaction.

• I Name and identify elements involved in chemical reactions.

• H Write word equations and predict name of product.

REACTIONS OF METALLIC ELEMENTS

Copy and answer questions

• What are metal oxides?

• How are metal oxides formed?

• Name the reactants and the product in the formation of metal oxides.

Learning Outcomes

• L Plan a safe experiment to demonstrate the objective.

• I Plan a safe and fair test for the experiment stated in the objective and write the work equation for the reaction.

• H Critically evaluate the plan you have written in terms of safety and fair testing.

PRACTICAL REVIEW

• Discuss about chemical change, what elements and compounds were present?

ATOMS-ELEMENTS AND COMPOUNDS REVISION

Education

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