Bonding

Structure and bonding

Ionic bonding

Covalent bonding

Metallic bonding

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Giant covalent bonding

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Properties

Ionic bonding

Covalent bonding

Metallic bonding

Giant covalent bonding

malleable and ductile

High melting and boiling points, so it require a lot of heat
energy to break up the lattice.

Metals and non-metals react together to form ionic compound

Non-metals react together to form covalent compounds.

Ionic compounds are usually soluble in water.

When ionic compounds melted or dissolved in water, they conduct electricity

Low melting and boiling points

Covalent compounds tend to be insoluble in water.

Covalent compounds do not conduct electricity

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usually have high melting points.

e good conductors of heat and electricity.

Chemical formulas and reactions

Formula

Example: Magnesium chloride

The ions form a lattice with two chloride ions for each magnesium ion.
So the formula of the compound is MgCl2. It has no overall charge.
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Reactions

Example: carbon is heated
in oxygen, they react together to form carbon dioxide

Word equation: carbon + oxygen --> carbon dioxide
Chemical equation: C + O2 -->CO2

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Mole concept and chemical calculation

Balance of equation and conservation of mass

The law of conservation of mass states that no atoms are lost or made in a chemical reaction. That's why the number of each type of atom must the same on both sides

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The sum of the reactants is equal to the sum of the product

Solid

Liquid

Gas

Moles = Concentration x volume

Moles = Volume/Molar volume(24)

Moles = Mass/Molar mass

Reaction kinetics

Rates

Rate is a measure of the change that happens in a single unit of time.

Factors affects rates

concentration of a reactant

How to measure

the amount of a reactant used up per unit of time or
the amount of a product produced per unit of time.

temperature

surface area of a solid reactant

Energy change and reversible reaction

Energy changes in reactions

Exothermic reactions

Exothermic reactions give out energy. So there is a temperature rise.

Endothermic reactions

Endothermic reactions take in energy from their surroundings.

the products have lower energy than the reactants.

the products must have higher energy than the
reactants.

Breaking bonds takes in energy. Making bonds releases energy

Reversible reaction

A reversible reaction is endothermic in one direction, and exothermic
in the other. The same amount of energy is transferred each time.

equilibrium

When a reversible reaction is in equilibrium and you make a change,
the system acts to oppose the change, and restore equilibrium.

For exothermic, when the temperature increase equilibrium favours the product.
For endothermic, when the temperature increase equilibrium favours the reactants.

if the concentration of reactants is increased, the system will shift toward the products. If more products are added, the system will shift to form more reactants

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combustion of fuels

Fuels are substances that react with oxygen to release useful energy

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When elements has same bonding, same electron configuration. So the different isotopes will react in the same way