Chemistry Unit
Page 1: Chemical Equations
Equations Representing Reactions
NaNO3 + H2O
Mg-Br + SO2
CH3C C2H,OH
NaBH Na .HHO
CH2 - Br + Na2SO3
Page 2: Chemical Formulas and Compounds
Examples of Compounds
NO2, CO2 + H2O
CyH10 + O2
CH3, H3, H, OH
1Zn + CuSO4 → ZnSO4 + Cu
Page 3: Elements, Mixtures, and Compounds
Definition of Terms
Element: A pure substance made from one type of atom (e.g., carbon).
Atom Types:
Single Atoms: Atoms of some elements do not bond with others; e.g., helium.
Molecules of Elements: Atoms of the same element bond together (e.g., O2).
Compounds: Formed when different elements bond, always existing as molecules.
Page 4: Mixtures
Mixture Definition: Made from different substances that are not chemically bonded.
Types of Mixtures:
Mixture of Elements
Mixture of Compounds
Mixture of Elements and Compounds
Page 5: Atomic Structure
Basic Components
Atoms:
Nucleus: Contains protons (+) and neutrons (0).
Electrons (-): Orbit the nucleus.
Atomic Characteristics
Atomic Number: Number of protons (e.g., O = 8, Na = 11).
Atomic Mass: Total count of protons and neutrons.
Page 6: Practice on Atomic Structure
Test Yourself
Fill in Definitions:
Atomic number = number of protons.
Atomic mass = total of protons and neutrons.
Page 7: Isotopes
Definition: Atoms of an element with different neutron numbers but same proton number.
Example:
Atomic Number vs. Mass Number calculated for isotopes.
Page 8: Completing Atomic Tables
Table for Sodium (Na):
Protons = 11, Neutrons = 12, Electrons = 11.
Examples for other elements: Protons, Neutrons, Electrons.
Page 9: Electronic Arrangements
Energy Levels
Filling Order: Lower energy level first.
Sodium Example:
Electronic structure as 2, 8, 1.
Page 10: Drawing Electronic Structures
Drawing Guidelines
Show nucleus as a black dot, shells as circles, electrons as dots or crosses.
Page 11: Questions and Match-Up
Make links between elements and their atomic structures.
Page 12: Historical Models of the Atom
Key Scientists and Models
John Dalton (1803): Proposed atomic theory with indivisible atoms.
J.J. Thomson: Discovered the electron and proposed the plum pudding model.
Ernest Rutherford: Nuclear model indicating a dense nucleus.
Niels Bohr: Electrons orbiting in shells.
Page 15: Mendeleev and the Periodic Table
Development of Periodic Table
Mendeleev’s Arrangement: Based on atomic mass, leaving gaps for undiscovered elements.
Modern Periodic Table
Elements organized by increasing atomic number, grouped by properties.
Page 17: Metal and Non-Metal Properties
Metals
Characteristics: Shiny, conductive, malleable, dense, sonorous.
Non-Metals
Characteristics: Dull, insulators, brittle, various states at room temperature.
Page 19: Group 1 Metals
Physical Properties
Soft, low melting points, low densities.
Chemical Properties
React with water to form hydroxides.
Page 21: Halogens and Noble Gases
Group 7: Halogens
Reactivity decreases down the group.
Group 0: Noble Gases
Unreactive and exist as single atoms.
Page 25: Chemical Reactions and Conservation of Mass
Definitions
Reactants: Starting substances.
Products: Substances formed.
Law of Conservation of Mass
Total mass of reactants = Total mass of products.
Page 27: Reactivity Series
Understanding Reactivity
Order of Reactivity: Most reactive to least reactive based on reactions with water and acids.
Page 30: Displacement Reactions
Basic Definition
A more reactive metal displaces a less reactive metal in a compound.
Page 31: pH Scale and Neutralisation
Understanding pH
Acids, bases, and neutral solutions identified by indicators.
Neutralisation Reaction
Acid + Base → Salt + Water
Page 33: Types of Neutralisation Reactions
Reactions involving metal oxides, hydroxides, and carbonates producing different products.
Page 36: Thermal Decomposition
Definition
Breaking down compounds with heat to form new products, typically a metal oxide and CO2.
Page 39: Energy Changes in Reactions
Exothermic vs Endothermic
Exothermic: Energy released, temperature increase.
Endothermic: Energy absorbed, temperature decrease.
Page 46: Conservation Law and Changes in Mass
Key Principles
Mass of reactants equals mass of products; conservation in chemical reactions confirmed by experimental evidence.