Presentation on theme: "Atoms, IONS and Molecules (By Sumiati)). Objectives 1. The definition of atoms, molecules, and ions 2. The relationship of atoms, molecules, and ions."— Presentation transcript:
Objectives 1. The definition of atoms, molecules, and ions 2. 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 ulangan Jum”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 Classification Element = 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,
23.3 Representing an Atom of an Element Using chemical symbols H C N O NaClCu He Li B F Ne Mg
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 SymbolRelative charge Protonp+1 Neutronn0 Electrone
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. X Z A chemical symbol mass number proton number
Kelompok kimia 8B Kelompok 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 5 Kelompok 5 ; dika ….. Atom; Rizki, lia, afi, imae, senopati…nilai 78+4 Kelompok 6 : aldi …..ion:Reza,Rian,Ayu,Monika,Rara.. Nilai 80+5 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:
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
Cl 35 Na H C P Ca Fe Al S 23 1 12 40 56 27 32 11 1 6 15 26 13 16 20
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 1 Magnesium 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 – MgMg 2+ Magnesium atomMagnesium ionElectrons
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 atomMagnesium ion Number of protons12 Number of electrons1210 Net charge0+2
23.6 What are Ions? Example 2 A 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 atomChloride ion Number of protons17 Number of electrons1718 Net charge0 – 1 35 + e - ClCl - Chlorine atomChloride ionElectron 17
23.6 What are Ions? The table below shows some ions formed by common atoms: ElementChemical symbolIon formed HydrogenHH+H+ SodiumNaNa + PotassiumKK+K+ AluminiumAlAl 3+ CalciumCaCa 2+ MagnesiumMgMg 2+ OxygenOO 2- ChlorineClCl - BromineBrBr - SulphurSS 2-
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 MoleculeMolecular diagramMolecular model (ball and stick) Hydrogen gas H 2 Oxygen gas Nitrogen gas H O N H O N
Molecules of compounds MoleculeMolecular diagramMolecular model (ball and stick) Water Carbon dioxide Ammonia Hydrogen chloride H N O H C OO HH H Cl H