Atomic Structure Flashcards
Which letter is used to represent the atomic number of an atom?
Z
What is the atomic number of an element?
Number of protons in an atom
Represents the elements identity
What letter represents mass number?
A
What is meant by mass number?
Number of protons + number of neutrons
What is meant by relative atomic mass?
Average mass of all isotopes of an element relative to ¹/₁₂ the mass of a Carbon-12 atom
What is meant by an isotope?
Atoms of an element containing the same number of protons, but different number of NEUTRONS.
Still have the same chemical properties
What is the different between physical properties and chemical properties? Give examples
Physical properties = MP/BP, density, electrical conductivity
Chemical properties = reactivity, acidity, flammability
(HOW IT REACTS)
What is meant by relative molecular mass?
The average mass of a molecule relative to 1/12 the mass of one atom of carbon-12
What is meant by a nucleon?
A sub-atomic particle found in a nucleus
protons + neutrons
Describe where the particles below are found, their relative mass, and their charge
(a) Protons
(b) Electrons
(c) Neutrons
Particle Location Relative Mass Relative Charge
Proton Nucleus 1mu 1+
Electron Energy levels negligible 1/1840 1-
Neutron Nucleus 1mu 0
State why the precise relative atomic mass quoted in the table for the ¹²C isotope is exactly 12.0000 [1 mark]
MARK SCHEME:
By definition [1]
The standard / reference value or isotope [1]
Describe the plum pudding model
Atoms consisted of a sphere of positive charge, with small negative charges distributed evenly within it
