C1 - Atomic Structure and the Periodic Table Flashcards
5 methods through which mixtures can be separated.
Filtration
Crystallisation
Simple Distillation
Fractional Distillation
Chromatography
Plum Pudding Model.
The atom is a ball of positive charge with negative electrons embedded in it.
Describe how the Bohr/nuclear model and how it came about.
The nuclear model suggests that electrons orbit the nucleus at specific distances (shells) - it came about from the alpha scattering experiments.
Later experiments led to the discovery of smaller, positive particles in the nucleus; what are these particles called?
Protons.
What did James Chadwick provide evidence for?
The existence of neutrons in the nucleus.
Describe the structure of an atom.
The atom has a small central nucleus made up protons and neutrons around which there are electrons on the shells.
Explain why atoms are electrically neutral.
They have the same number of electrons and protons.
What is the radius of an atom?
0.1 nm.
Where is the majority of mass of an atom?
The nucleus.
Isotopes.
Atoms of the same element (same atomic number) that have a different number of neutrons (different mass number).
Ions.
Charged Particles. They are formed when atoms lose electrons or gain electrons.
Metal Properties.
Shiny
High Melting/Boiling Point
Conductor
High Density
Non-Metal Properties.
Low Melting/Boiling Point
Insulator
Dull
Low Density
What is formed when a metal reacts with a non-metal?
An ionic compound.
What is formed when a non-metal reacts with a non-metal?
A molecular compound containing covalently bonded atoms.
Solute.
A substance that is dissolved in a solvent.
Elements that react to form positive ions are…?
Metals.
Elements that do not form positive ions are…?
Non-metals.
3 Characteristics of Group 1 (Alkali Metals).
One electron in their outer shell.
Low Density.
Soft.
How do Group 1 elements react with non-metals?
They form ionic compounds which are soluble white solids which form colourless solutions - they all have one electron in their outer shell.
How do Group 1 elements react with water?
They release hydrogen and form hydroxides which dissolve to from alkaline solutions; they react vigorously with water, fizzing and moving around in the surface of the water.
How does the reactivity change moving down the Group 1? Why?
Reactivity increases as the atoms get larger and the distance between the nucleus and the outer electrons increases and thus attraction from the nucleus decreases, allowing them to more easily lose electrons.
3 Characteristics of Group 7 (Halogens).
7 electrons in the outer shell.
Coloured vapours.
Diatomic molecules.
State five Group 7 elements and states of matter of molecules they form.
Fluorine - pale yellow gas.
Chlorine - pale green gas.
Bromine - dark brown liquid.
Iodine - grey solid.
State three changes that occur in Group 7 as one moves down the group.
Higher relative mass.
Higher melting and boiling points.
Less reactive.
Describe the trend in reactivity in Group 7
Reactivity decreases down the group. The atoms get larger, so an incoming electron will be less tightly held by the attractive forces from the nucleus.
Catalyst.
A chemical substance that increases the rate of a chemical reaction.
State the colours of flames observed when Lithium, Sodium, and Potassium burn in Oxygen.
Lithium - Crimson-red.
Sodium - Yellow-orange,
Potassium - Lilac.
Describe the properties of Group 0 (Noble Gases). Discuss the trend in boiling point down the group.
Non-metals, bases, low boiling points, unreactive due to full outer shell.
The boiling point increases down the group, as the atoms get heavier.
