Unit B: Section 3.0 Flashcards
What is a chemical formula?
A combination of symbols that we use to identify an element
What does the chemical formula identify?
The elements in the compound and the amount of each element
Why did they create a system to name chemicals?
Because different scientists called it different things and it caused great confusion
Who created a naming system for chemicals?
Guyton du Morveau
What did Guyton du Morveu decide?
Always put the metal elements first
What does IUPAC stand for?
International union of pure and of applied chemistry
What does IUPAC do?
They determine the appropriate name for each chemical
What do chemical formula’s always end with?
-ide
What does the subscript of a chemical formula represent?
the amount of atoms that are present
What does no subscript indicate?
Only on atom is present
How do you indicate the state of a formula?
By putting a s/l/g in brackets as a subscript
What does a subscript (aq) indicate?
That it is dissolved in water
How many electrons can fit in the first shell of an atom?
2
How many electron can fit in the second shell of an atom?
8
How many electrons can fit in the third shell of an atom?
8 or 18
What is an ionic compound?
Pure substances formed as a result of the attraction between particles of the opposite charges called ions
what is an ion?
An atom that has become electrically charged because it has lost or gained an electron
What is a positive ion?
an ion that has lost one or more electron
What is a negative ion?
An ion that has gained one or more electron
What are polyatomic ions?
A group of atoms acting as one
What are the properties of Ionic compounds?
Ions High melting points Good conductors Disting crystal shape Solids at room temperature
What do ions form when they combine?
A crystal
Where do you write the ionic charge in a formula?
As a subscript
When should you use roman numerals when writing the ion charge?
When it has more than one common ion charge
