Year 10 Chemistry

The main difference between a chemical and physical change,Chemical changes form a new substance, physical changes do not.

Signs of a chemical change,Colour change, heat produced/observed, gas bubbles, solid disappears, explosion, new solid forming.

Characteristics of solids,- Definite shape

• Don't flow, hard to compress

• Can expand if heated

• Strongly bonded particles

• Vibrate faster when heated.

Characteristics of liquids,- No definite shape

• Can flow to take shape of a container

• Difficult to compress

• Weakly bonded particles

• Vibrate & move more than solids.

Characteristics of gases,- No fixed shape

• Will spread to completely fill container

• Compressible

• No bond between particles

-More energy than liquids or solids

-Fly around

Melting point,The temperature at which a solid becomes liquid.

Boiling point,The temperature at which a liquid becomes gas.

Number of subatomic particles in an atom.,Three.

Protons,Positive particles found in the nucleus.

Neutrons,Neutral particles found in the nucleus.

Electrons,Negative particles found outside the nucleus.

Isotopes,An atom that contains the same number of protons but different numbers of neutrons.

Elements,A pure substance containing only one type of atom.

Compound,Two or more different atoms bonded together.

Molecule,Two or more non-metal atoms bonding by sharing electrons.

Electronic configuration,The arrangement of electrons around the nucleus.

The amount of electrons the first shell can hold,Two.

The amount of electrons the second shell can hold.,Eight.

The amount of electrons the third shell can hold.,Eighteen.

The amount of electrons the fourth shell can hold.,Thirty-two.

Elements in the same group on the periodic table have the same number of ___.,Valence electrons.

Elements in the same period on the periodic table have the same number of __.,Occupied electron shells.

Characteristics of metals.,- Solid at room temp (except mercury)

• Can be polished

• Good heat & electricity conductors

• Malleable (bendy)

• Ductile (Stretchy)

• High melting temp (except mercury)

Characteristics of non-metals,- Can't be polished (dull/glassy)

• Brittle

• Not bendy

• Can't conduct

• Melt at low temp

• Many are gases at room temp.

Electronegativity,The ability to attract an electron to form a bond.

Ionisation energy,The amount of energy required to remove the first valence electron.

Ion,A charged atom.

Cation,A positive ion formed when valence electron(s) are lost

Anion,A negative ion formed when valence electron(s) are gained.

Ionic bond,Electrostatic force of attraction between cations and anions.

Ionic compound,Compound made up of ions bonded by electrostatic attraction.

The goal of most atoms,To have a full valence shell.

Metals tend to ____ electrons to form _.,Lose, cations.

Non-metals tend to ____ electrons to form ______.,Gain, anions.

Ionic bonding,A metal (cation) bonding to a non-metal (anion) through the transfer of electrons.

Properties of ionic compounds,- High melting & boiling points

• Solid at room temp

• Hard but brittle, which makes it neither malleable or ductile

• Do not conduct electricity as a solid but can conduct as a liquid or when dissolved

• Vary from soluble to insoluble

• Not soluble in non-polar solvents like oil

Metals like to give away electrons because ___.,They have low ionisation energy.

In solid form, metals are arranged in a _.,Crystal lattice.

The cations in an arrangement of metals are held together…,By the electrostatic attraction between the sea of electrons and cations.

Properties of metals,- Malleability (can be bent/hammered into shapes)

• Ductility (can be stretched into a wire)

• Electrical & heat conductivity

• High melting & boiling point

• Lustre (shiny)

Alloys,Mixing another element into a metal, usually 90% metal and a small portion of the alloying agent.

How to produce an alloy,1. Melt the substances

2. Mix them together

3. Cool the mixture

Interstitial alloys,A smaller element added to a metal, commonly carbon. The metal becomes less bendy, harder, and melts easier.

Substitutional alloys,Elements of a similar size added to the metal. The metal becomes strong and hard but it melts easier.

Annealing,Heating a metal to a specific temperature and allowing it to cool slowly to room temperature. Forms large metal crystals & makes the metal more bendy and stretchy.

Quenching,Heating to a specific temperature and cooling in cold water. Forms small crystals and increases hardness and strength.

Tempering,Quench and then anneal. Forms medium crystals and increases hardness, brittleness, strength, and ductility.

Covalent bonding,Bonding between two non-metals through the sharing of electrons.

Hydrocarbons,Made of carbons and hydrogens ONLY.

Alkanes,Hydrocarbons with only single covalent bonds

Meth-,Only 1 carbon

Eth-,2 carbons

Prop-,3 carbons

But-,4 carbons

Pent-,5 carbons

Hex-,6 carbons

Hept-,7 carbons

Oct-,8 carbons

Non-,9 carbons

Dec-,10 carbons

-ane,Single bonds only

-ene,Has a double bond

-yne,Has a triple bond

Isomer,Has the same molecular formula but have a different structural formula and a different name.

Haloalkanes,Chlorine, Fluorine, Bromine, or Iodine covalently bonded to an organic compound.

Alcohols,Contain a hydroxyl functional group (OH).