C3 Flashcards
How do you write the formula of metal elements?
The formulae of metal elements are always written as empirical formulas as metals exist as giant metallic lattice
Non metal elements in group 0…
Exist as individual atoms.
They are attracted to eachother by weak intermolecular forces
Their chemical formulae are their chemical symbols
Non metal elements in group 7…
Non metal elements in group 7 exist as diatomic molecules attracted to eachother by week intermolecular forces.
These elements all contain a subscript 2
Other non metal elements…
Exist as giant covalent structures and simple molecules
What does the molecular formula for a simple covalent compound show?
The symbols for each element
The number of atoms in one of its molecules
Metals in groups 1, 2 and 3 produce…
Positive ions with the number of charges equal to their non-IUPAC number
Transition metals…
Produce positive ions with a 2+ charge
Non metals in group 5,6 and 7 produce…
Negative ions in which the number of charges equals 8 - noniupac number
What is the law of conservation of mass?
Atoms cannot be created or destroyed by chemical reactions.
The same atoms are present at the start and end of a reaction.
They are joined in a different way so the total mass stays the same
What is a closed system?
A container in which no substances can enter or leave during the reaction
What is a diatomic molecule?
2 atoms covalently bonded together
What is a non-enclosed system?
Substances can leave or enter the reaction mixture,
This usually happens in an open container when the reaction involves a substance in the gas state.
The gas escaped so the mass appears to go down during the reaction
What happens when a metal reacts with oxygen in the air?
The metal atoms combine with oxygen atoms in the air to form a metal oxide in the solid state.
What are state symbols?
State symbols show the physical state of each substance in a chemical reaction.
What does a balanced equation show?
How the atoms are rearranged in a reaction
The relative amounts of each substance involved
