A Simple Model Of The Atom, Symbols, Relative Atomic Mass, Electronic Charge And Isotopes Flashcards
State that everything is made of atoms and recall what they are
All substances are made of atoms, atoms contain protons, neutrons and electrons
Describe what elements and compounds are
Elements - a substance whose atoms all have the same number of protons
Compounds - when two or more elements chemically combine in a fixed ratio by mass
State that elements and compounds are represented by symbols; and use symbols and formulae to represent elements
A compound is represented using a formula, comprising symbols of elements. For example, water(H20), oxygen(O)
Write word equations and balanced symbol equations for chemical reactions, including using appropriate state symbols
State symbols are written after the formula of each substance
Describe what a mixture is
A compound made up of two or more chemical components that are not chemically linked
Name and describe the physical processes used to separate mixtures and suggest suitable separations techniques
Chromatography - a process for separating components of a mixture
Distillation - the process of separating the components of a liquid mixture through selective evaporation and condensation
Evaporation - the process of turning from liquid to vapour(gas)
Filtration - the process in which solid particles in a liquid or gaseous fluid are removed by the use of a filter medium that permits the fluid to pass through but retains the solid particles
Describe how the atomic model has changed over time due to new experimental evidence, including the discovery of the atom and scattering
The plum pudding model persisted until Ernest Rutherford discovered the existence of the nucleus in the alpha particle scattering experiment. With the discovery of the nucleus, atoms could no longer be considered as solid spheres, so the accepted model changed to the nuclear model
Describe the difference between the plum pudding model of the atom and the nuclear model of the atom
Plum pudding - there is a positive sphere with negative charge randomly placed within a sphere, there is no empty space
Nuclear model - central positive, tiny nucleus, with mostly empty space and lots of negative charges a long way from the nucleus
State the relative charge of protons, neutrons and electrons and describe the distribution of mass in an atom
Relative charge -
Protons +1
Neutrons 0
Electrons -1
Mass distribution -
Most of an atom is concentrated in its nucleus. Protons and electrons have electrical charges that are equal and opposite
State the relative masses of protons, neutrons and electrons and describe the distribution of mass in an atom
Relative mass -
Proton +1
Neutron +1
Electron 0.0005
Distribution of mass in an atom -
Most of the mass of an atom is concentrated in its nucleus
Calculate the number of protons, neutrons and electrons in an atom when given its atomic number and mass number
Number of protons - atomic number
Number of electrons - atomic number
Number of neutrons - mass number-atomic number
(Mass number is the number above the element
Atomic number is the number below the element)
Describe isotopes as atoms of the same element with different number of neutrons
Isotopes are members of a family of an element that all have the same number of protons but different number of neutrons
Define the term relative atomic mass and why it takes into account the abundance of isotopes of the element
The relative atomic mass of an atom is a weighted average of the masses of the atoms of the isotopes
Calculate the relative atomic mass of an element given the percentage of abundance of its isotopes
Multiply each isotopic mass by its abundance, add all the values together and divide the total value by 100 percent
Describe how electrons fill energy levels in atoms, and represent the electron structure of element using diagrams and numbers
The electrons in an atom occupy the lowest available energy level first
