Junior Cert Revision

What is an element?

Matter made up one type of atom only that can’t be split into anything simpler by chemical means

What is a compound?

Matter made up of 2 or more different types of elements chemically combined

What is a molecule?

Combination of 2 or more atoms chemically bonded together

What are the two types of molecules

Molecule of an element, molecule of a compound

What is a molecule of an element

2 or more of the same atoms chemically combined

What is a molecule of a compound

2 or more different atoms chemically combined

True or false: All compounds are molecules

True

True or false: All molecules are compounds

False

What are diatomic molecules?

A group of elements that exist in nature not as atoms, but as 2 atoms of the same element bonded to each other

What are the elements that are diatomic molecules?

Hydrogen, Nitrogen, Fluorine, Oxygen, Iodine, Chlorine, Bromine

What does this diagram show?

Atom of an element

What does this diagram show?

Molecule of an element

What does this diagram show?

Molecule of a compound

What is a mixture

2 or more different particles mingled together, but not chemically combined

True or false: mixtures have distinct properties

False

True or false: Mixtures are the same sample to sample

False: Mixtures vary from sample to sample

What are the two different types of mixtures

Homogeneous and heterogeneous

What is a heterogeneous mixture

A mixture that is not the same throughout

What is a homogeneous mixture

A mixture that is the same throughout

What does filtration do

Separate insoluble solids from liquids

What are the two types of filtration

Gravity and suction/vacuum

What is gravity filtration

Uses gravity to pull water through filter paper

What is suction/vacuum filtration

Uses a buchner flask as opposed to a conical flask. Faster than gravity filtration

What is the name of the solid separated from the liquid during filtration

Residue

What is the name of the liquid separated from the solid in filtration

Filtrate

What is evaportation

Separate a soluble solid from a liquid by evaporating the liquid, leaving the solid behind

What is distillation

Separates components of a mixture based on their boiling points

What are the steps to distillation

1. In the distilling flask, mixture heated & liquid with lower boiling point evaporated

2. Use thermometer to monitor temperature

3. Liebig condenser cools vapour to condense it

4. Receiving flask collects distillate (evaporated, cooked and condensed liquid)