[ chem module 2 key definitions ] Flashcards
What is the atomic number?
The number of protons an element has.
What is an isotope of an element?
An isotope of an element will have the same number of protons and electrons but a different number of neutrons.
What is an ion?
An ion is a charged atom which either lost or gained electrons.
What is the difference between a cation and anion?
Cation is a positive ion which lost electrons.
Anion is a negative ion which gained electrons.
[Try remember anion as an onion which is bad boo hoo therefore negative]
What is the relative isotopic mass?
The mass of an isotope relative to 1/12th the mass of a carbon-12 atom.
What is the definition of relative atomic mass?
The weighted mean mass of an atom of an element relative to 1/12th the mass of a carbon-12 atom.
How do you calculate the relative atomic mass?
Contribution from isotope x percentage / 100
For example, (75.78x35) + (24.22x37) / 100
What is the formulae for an ammonium ion?
NH4+
What is the formulae for a hydroxide ion?
OH-
What is the formulae for a nitrate ion?
NO3-
What is the formulae for a carbonate ion?
CO3 2-
What is the formulae for a sulfate ion?
SO4 2-
Example question: What is the formulae for zinc chloride?
ZnCl2
Example question: What is the formulae for aluminium sulfate?
Al2(SO4)3
What is the avogadro constant?
The number of particles in each mole of carbon-12 atom.
6.02x 10^23