Test one: basic chem and ionic bonding Flashcards
(20 cards)
Alloys
Alloys are made of metal combined with a small amount of other element. The main element is called the base metal
Particle Theory of Matter
All matter has mass and takes up space
All matter is made up of particles that move
Particles that make up a substance can exist as a solid, liquid or gas
The amount of heat energy the particles have determine how much they move
Temperature and Energy of particles
As the temperature increases, the average energy of the particles increases
As the substance change state, there is no increase in temperature, the extra energy is overcoming forces of attraction between particles
Mixture
A mixture is two or more substances combined in any proportion
Pure Substance
A substance is described as pure if it cannot be separated by a physical change into two or more compounds.
Compounds
Compounds can be split into tow broad groups where the basis classification is structure
Ionic Compounds
formed from metal/non metal combinations where the positive and negative ions are held together by strong electrostatic forces of attraction in a regular lattice
Physical change
During a physical change no new substance is formed and can be reversed by physical means
Chemical Change
During a chemical change a new substance is formed
signs of a chemical change include: temperature change, heat given off, colour change, gas given off, effervescence, precipitate (insoluble solid)
Element
an element is a pure substance made up of 1 type of atom
The periodic Table
elements in the same group have the same number of electrons in their outer shell. Horizontal rows are called periods Group 1: Alkali Metals Group 2: Alkali Earth Metals Group 7: Halogens Group: 8: Nobel gases or inert gases The block between group 2 and 3 are transition metals period 6 - lanthanides period 7 - actinides
Electronegativity
Measures the pull of an atom of an element on electrons
the stronger the pulling power the higher the electronegativity
Fluorine is the most electronegative element
Increases across a period and decreases down a group
Atomic Radius
Decreases across a period
increases down a group
as the electronegativity increases the atomic radius decreases
Ionisation Energy
The first ionisation energy for any element is the amount of energy required to remove the most loosely held electron from one mole of gaseous atoms to produce one mole of gaseous ions with 1+ charge
Ionisation energy increases with electronegativity
Metallic Nature
Metals tend to lose electrons in chemical reactions to form positively charge ions called cations. decreases across the the periodic table and increases down a group
Naming Ionic Compounds
The ending of the name for the non metal changes for monatomic ions (single element ions) the ending is ide. ie. chlroide, oxide, sulfide, nitride
NO3 (-1)
SO4 (2-)
CO3 (2-)
Metallic Bonding
The outmost or valence electrons in metal atoms move freely within a 3D lattice or patter of positively charged metal ions. The electrons from each metallic atom are found in a common pool and are free to move around between cations. They are referred to as delocalised electrons. The negatively charged electrons are attracted to all positively charged metal ions in the lattice and this electrostatic force attraction holds the lattice together
Properties of metallic bonds
Good conductors of electricity and heat High melting and boiling point Dense Malleable (can be shaped) and ductile (can be drawn into wire) Lustrous
Ionic bonding
Metals and non metals can react together because the electrons lost by metals can be taken up by the non metals so both elements have a full valence shell. The metal becomes a positive ion and the non metal becomes a negative ion. Very strong bond
Properties of Ionic Compounds
Non conductors of electricity when solid
conductors of electricity when molten or in aqueous form
High melting and boiling point
hard and brittle
