Atoms, IONS and Molecules (By Sumiati))

Atoms, IONS and Molecules (By Sumiati))

Objectives1. The definition of atoms, molecules, and ions2. The relationship of atoms, molecules, and

ions.3. The Examples of substances consisting of

atoms, molecules, and ions.4. The differences of element molecules and

compound molecules.5. The examples of simple molecules in

everyday life.

Kelas 8B ulanganJum”at depan, 18 nov .. Ulangan 3 bab.

1. sistem pernapasan (bab4)2. sistem peredaran darah (bab 5)3. atom, ion dan molekul (bab 1 kimia)

bilingual

What is a matter/substances?Matter or substances is everything having mass and occupy a space.

Matter ClassificationElement = substance that cannot be broken

down into simpler substance by chemical methods. Ex: O2, O3, H2, N2

Compound = the combination of some elements formed through a chemical reaction. H2O, CO2, C6H12O6

Mixtures = substances consisting of two or more substances formed without a chemical reaction. Ex” teh manis, juice,

Particle of MatterAtomsIonsMolecules

Ulangan bab 4,5 1 kimia

What is an Atom? An atom is the smallest particle of an element.

An atom has an average size of about 0.0000000001 m or

1 x 10–10m.

ATOMS MODEL(John Dalton)

ATOMS MODEL(J.J Thomson)

ATOMS MODEL

ATOMS MODEL(Niels Bohr)

ATOMS MODEL N=2-5 O=2-6

23.3 Representing an Atom of an Element Using chemical symbols

H C N O Na Cl Cu

He

Li

B

F

NeMg

23.4 What is an Atom Made Up of? Each atom is made up of even smaller

particles.These particles are called sub-atomic

particles.Types of sub-atomic particles – protons,

electrons and neutrons

23.4 What is an Atom Made Up of? The table below summarises the

properties of protons, neutrons and electrons.

Sub-atomic particles

Symbol Relative charge

Proton p +1

Neutron n 0

Electron e -1

23.5 Proton (Atomic) Number and Mass Number

The atomic number or proton number is the number of protons in an atom.

(=electron number)The mass number is the total number of

protons and neutrons in an atom.

XZ

A

chemical symbol

mass number

proton number

Kelompok kimia 8BKelompok 1 ; dzikra,11,21,29,3,38,18, … ion…(75) Kelompok 2

; byan,aci.adit,maska,nabjas,tiara,dinda …molekul… …(nilai 78)

Kelompok 3 ; ageng.1,7,9,10,19,16,20 …atom (nilai 80)Kelompok 4 : muthia, mine, rania, clara, mirshaan, sule

molekul (bonus 5Kelompok 5 ; dika ….. Atom; Rizki, lia, afi, imae, senopati…

nilai 78+4Kelompok 6 : aldi …..ion:Reza,Rian,Ayu,Monika,Rara .. Nilai

80+5Tugasnya: lirik lagu dikumpul sekarang …. Buat lagu…

atom, ion, molekul. Yg ngumpul sekarang sarusnya 10.Lirik lagu mengenai semua pembahasan tentang atom, ion,

molekul. Ketua kelompok ambil undian:

Tugasnya: lirik lagu dikumpul sekarang …. Buat lagu… atom, ion, molekul. Yg ngumpul sekarang sarusnya 10.

Lirik lagu mengenai semua pembahasan tentang atom, ion, molekul. Ketua kelompok ambil undian:

Lagu in english…Hari selasa depan dinyanyikan ke depan

berkelompok Menyanyi sambill bergaya

Periodic Table

Cl35

Na

H

C

P

Ca

Fe

Al

S

23

1

12

40

56

27

32

11

1

6

15

26

13

1620

23.6 What are Ions?When an atom loses or gains electrons, we

say that an ion is formed.An ion is an atom that carries a positive or

negative charge as a result of having lost or gained one or more electrons.

Atoms which lose electrons will have a net positive charge. Hence, they form positive ions.

+ + e –

neutral atom

atom with net positive charge

electron lost by atom

23.6 What are Ions?Atoms which gain electrons will have a

negative charge. Hence, they form negative ions.

-+ e –

neutral atom atom with net

negative charge

electron gained by atom

23.6 What are Ions?Example 1Magnesium chloride is a compound made from two kinds of ions – magnesium ions, which have a positive charge, and chloride ions, which have a negative charge.A magnesium atom has the chemical symbol, Mg. A magnesium atom (an atom of a metal) loses two electrons to form a magnesium ion in its compound.

+ 2e –Mg Mg2+

Magnesium atom Magnesium ion Electrons

23.6 What are Ions?Example 1

A magnesium ion has 12 protons and 10 electrons. Hence, it has a net positive charge of +2.

Magnesium atom Magnesium ion

Number of protons 12 12

Number of electrons 12 10

Net charge 0 +2

23.6 What are Ions?Example 2A chlorine atom has the chemical symbol, Cl.A chlorine atom (an atom of a non-metal) gains an electron to form a chloride ion in its compound.

A chloride ion has 17 protons and 18 electrons. Hence, it has a net negative charge of –1.

Chlorine atom Chloride ion

Number of protons 17 17

Number of electrons 17 18

Net charge 0 – 1

35

+ e-Cl Cl-Chlorine atom Chloride ionElectron

17

23.6 What are Ions?The table below shows some ions formed by

common atoms: Element Chemical symbol Ion formed

Hydrogen H H+

Sodium Na Na+

Potassium K K+

Aluminium Al Al3+

Calcium Ca Ca2+

Magnesium Mg Mg2+

Oxygen O O2-

Chlorine Cl Cl-

Bromine Br Br-

Sulphur S S2-

23.7 What are molecules? A molecule is made up of two or more

atoms chemically combined together. Molecules of elements usually consist of

a fixed number of one type of atom chemically combined together.

Molecules of compounds contain a fixed number of different types of atoms chemically combined together.

Molecules of elements Molecule Molecular diagram Molecular model

(ball and stick)

Hydrogen gas

H2

Oxygen gas

Nitrogen gas

H

O

N

H

O

N

Molecules of compounds Molecule Molecular diagram Molecular model

(ball and stick)

Water

Carbon dioxide

Ammonia

Hydrogen chloride

H

N

OH

CO O

H H

H

ClH

GRATITUDE