Year 11 MAH

 Matter is used to describe all materials in our world – may be solid, liquid, or gases  Atoms are the building blocks of matter VERY SMALL!! Cannot be seen with a powerful microscope

 The atom is made up of three subatomic particles  The number of electrons, protons and neutrons is given to us by the mass number and the atomic number

 The overall charge on an atom is zero i.e the protons cancel out the number of electrons.

Li 3 7 ATOMIC NUMBER How many protons in nucleus. MASS NUMBER How many protons and neutrons are in the nucleus.

 Electrons orbit the nucleus in shells ◦ 2 electrons fit in the first shell ◦ 8 electrons fit in the second shell ◦ 8 electrons fit in the third shell ◦ 2 electrons fit in the fourth shell

Nucleus = Protons and Neutrons 1 st Shell = 2 electrons 2 nd Shell =8 electrons 3rd Shell =8 electrons 4th Shell = 2 electrons

 We know that atoms with full shells of electrons e.g. 2, 2.8, are stable  Atoms gain or loose electrons to become stable = they become ions  Example on board of Mg, Na, Li

Thinly spread around the outside of the atom. Very small and light. Negatively charged. Found orbiting the nucleus in layers called shells. Able to be lost or gained in chemical reactions. The nucleus is: Electrons are: Dense – it contains nearly all the mass of the atom in a tiny space. Made up of protons and neutrons. Positively charged because of the protons.

Elements consist of one type of atom, but sometimes these atoms can be slightly different. mass number is different atomic number is the same Atoms that differ in this way are called isotopes. Although atoms of the same element always have the same number of protons, they may have different numbers of neutrons.

The isotopes of an element are virtually identical in their chemical reactions. The uncharged neutrons make no difference to chemical properties but do affect physical properties such as melting point and density. Natural samples of elements are often a mixture of isotopes. This is because they have the same number of protons and the same number of electrons.

Most naturally-occurring carbon exists as carbon-12, about 1% is carbon- 13 and a much smaller amount is carbon protons 6 neutrons 7 electrons 6 protons 6 neutrons 8 electrons 6 protons 6 neutrons 6 electrons

About 75% of naturally-occurring chlorine is chlorine-35 and 25% is chlorine protons 18 neutrons 17 electrons 17 protons 20 neutrons 17 electrons

 Element: is a substance made of one type of atom  Molecule: Group of atoms bonded together because the atoms share electrons e.g. H 2, O 2, N 2  Compounds: is a substance where non-identical atoms are bonded e.g. H 2 O  Mixtures: Made of different elements which can be easily separated

 In an atom – protons are equal to the number of electrons THIS MAKES AN ATOM NEUTRAL HOWEVER, AN ATOM IS NOT STABLE UNLESS IT HAS A FULL OUTER SHELL OF ELECTRONS

 Sodium (Na) Na Sodium has eleven protons and 11 electrons ELECTRON ARRANGEMENT: 2, 8, 1 Atoms with partly filled shells tend to be unstable and reactive

 Sodium (Na) Na Sodium has eleven protons and 11 electrons ELECTRON ARRANGEMENT: 2, 8, 1 HIGHLY EXPLOSIVE

 Atoms lose or gain electrons to fill their outer shells to become more stable  Metals lose electrons to become POSITIVELY CHARGED = cations  Non-metals gain electrons to become NEGATIVELY CHARGED = anions

Electron arrangement: (partially full outer shell) Na 11 protons= electrons= -11 Total charge= 0 Sodium atom: 11 protons= electrons= -10 Total charge= +1 Sodium ion: one electron is lost Na + Electron arrangement: [2.8] + (full outer shell)

Electron arrangement: (partially full outer shell) 12 protons= electrons= -12 Total charge= 0 Magnesium atom: 12 protons= electrons= -10 Total charge= +2 Magnesium ion: Electron arrangement: [2.8] 2+ (full outer shell) two electrons are lost Mg 2+

Negative ions have a small ‘-’ symbol and a number by them to indicate how many electrons they have gained to fill their outer shell. For example: chloride ion = Cl - (not Cl 1- )chlorine atom = nitrogen atom = 2.5nitride ion = N 3- oxygen atom = 2.6 oxide ion = O 2- An atom that gains one or more electrons forms a negative ion. Non-metal atoms, such as chlorine, oxygen and nitrogen, form positive ions. The name of the ion is slightly different to that of the atom – it ends ‘– ide’.

Electron arrangement: 2.7 (partially full outer shell) F 9 protons=+9 9 electrons= -9 Total charge= 0 Fluorine atom: 9 protons= electrons=-10 Total charge= - 1 Fluoride ion: Electron arrangement: [2.8] - (full outer shell) one electron is gained - F

 When an atom loses or gains electron(s) to become stable we say that it has ionised or formed an ion and the charge that it has formed is called a valency  You might have noticed a pattern that the charges match up with a column on the periodic column  Elements that have full shells like carbon and silicon have no charge, they are relatively stable e.g. silicon for implants

 H +,K +, Na +, NH­ 4 +, Li +1, Cl - (chloride), OH -, NO 3 -, HCO 3 -, Mg +2, Ca +2, Zn +2, Fe +2, Pb +2, Cu +2, O -2 (oxide), S -2 (Sulfide), SO 4 -2, CO 3 -2, Al +3, Fe +3 and PO  Table of ions – write in the names  Nitrate, carbonate, sulfate, ammonium, bicarbonate, hydroxide  Pg. 56

Element Name Atomic Number Electron Config. Gain or Loose Electrons Ion Formula and Name Chlorine172, 8, 7Gain 1Cl -1 Chloride Oxygen 3 12 Sulfur Flourine Beryllium 11 Boron

Element Name Atomic Number Electron Config. Gain or Loose Electrons Ion Formula and Name Chlorine172, 8, 7Gain 1Cl -1 Chloride Oxygen82, 6Gain 2O -2 Oxide Lithium32, 1Loose 1Li +1 Lithium ion Magnesium122, 8, 2Loose 2Mg +2 Magnesium ion Sulfur162, 8, 6Gain 2S -2 Sulfide Flourine92, 7Gain 1F -1 Flouride Beryllium42,2 Loose 2Be +2 Beryllium ion Sodium112, 8, 1Loose 1Na +1 Sodium ion Boron52, 3Loose 3B -3 Boron ion

Year 11 MAH

 The Periodic Table was first invented in 1869 by Dmitry Mendeleyev.  It is a way of presenting all the elements to show their similarities and differences.

Select an element = Internet link ()

 There is a diagonal line that separates the metals from the non-metals.  Metals are on the left.  Non-metals are on the right.  Metalloids are in the middle of the metals and non-metals.

 Groups: Technical word for columns  Periods: Technical word for rows  INVESTIGATE: ◦ Write out the electron configurations for elements in group 1 e.g. Li, Na, K ◦ Write out electron configurations for elements in group 17 e.g. F, Cl and group 18 He, Ne, Ar ◦ WHAT DO YOU NOTICE!!

Elements in the same group have the same number of electrons in their outer most shell (valence shell) They react similarly Group 1 = VERY REACTIVE Video

Lithium and Nitrogen are in Period 2 – Write out their electron configurations and say how many electron shells there are Magnesium and Chlorine are in period 3 – Write out their electron configurations and say how many electron shells there are What do you think the ‘period’ tells us?

Noble Gases18 Halogens17 Alkali Earth Metals2 Alkali Metals1 Group NameGroup Number The big block in the middle of the Periodic Table is called the Transition Metals.

HHydrogenNaSodium HeHeliumMgMagnesium LiLithiumAlAluminium BeBerylliumSiSilicon BBoronPPhosphorus CCarbonSSulfur NNitrogenClChlorine OOxygenArArgon FFLuroinePPotassium NeNeonCaCalcium

 Ions are formed by atoms gaining or loosing electrons  Ions of opposite charge are attracted to each other  They form ionic bonds (metal and non-metal)  Ionic compounds are formed when a substance in which atoms are held together by ionic bonds

 The formula shows the ions present and the ratio of each ion in the compound  They are neutral!! ◦ the positive charges of the cations equals the negative charges of the anions

 The formula shows the ions present and the ratio of each ion in the compound  They are neutral!! ◦ the positive charges of the cations equals the negative charges of the anions ◦ WE HAVE TO BE ABLE TO WRITE THEM

 For ionic compounds, apply these rules: ◦ The metal ion's name does not change regardless of charge ◦ The non-metal's name ends in ide. ◦ Complex ions names generally end in ate

Compounds that contain ions are called ionic compounds. These compounds are usually formed by a reaction between a metal and a non-metal. Why do these substances react? Both the metal and non-metal atoms have incomplete outer electron shells and so are unstable. One or more electrons are transferred from each metal atom to each non- metal atom. The metal and the non-metal atoms end up with completely full outer shells and become very stable. The positive and negative ions are strongly attracted to each other. This electrostatic attraction is called an ionic bond.

 Comparison of charges on ions: When these elements react, Na loses one electron and forms a +1 ion, while Be loses two electrons and forms a +2 ion in order to adopt the stable electron configuration. The hydroxide carries a charge of -1.  Explanation of formation of compounds: An ionic compound is electrically neutral therefore all the positive charges must balance the negative charges.  Therefore it requires one OH -1 for each Na + ion but two OH -1 ions for each Be 2+ ion to form a neutral compound/ balance the charges.