What Is The Best Method To Classify a Chemical Substance?

Most efficient, way to result in quality data

chemical substances can be classified through their structure, state of matter, physical properties, chemical properties.

state of matter:
solid
liquid
gas

physical properties:

  • melting point of substance
  • boiling point
  • density
  • solubility
  • physical appearance

chemical properties:

  • how it reacts with other substances
  • acidity of basicity (pH)
  • reactivity with water, oxygen other chemicals

a chemical substance is a unique form of matter with constant chemical composition and properties

chemical substances can be categorized into elements and compounds. Elements are pure substances that consist of only one type of atom. Elements can not be broken down into simpler structures

Chemical compound, any substance composed of identical molecules consist of two or more atoms and or chemical elements

Possible methods:

Observations:
test physical state and appearance, note whether the substance is solid, liquid, gas, color texture and form.

Chemical Test:
Mix the substance with solutions to see if a precipitation (water) forms which showcases presence of ioins

Metallic (metal and metal)

Ionic Bonds (non metal and metal)

properties:

  • high MP/BP
  • Crystal lattice structure
  • solid form breaks easily into sheets
  • solid form do not conduct electricity
  • dissolve in solvents

covalent network:

  • Do not conduct electricity
  • High MP/BP
  • All solid form
  • Not malleable
  • Do not dissolve

Covalent Molecular bond (Non Metal and Non Metal)

Malleable

high MP/BP

high electrical conductivity

high thermal conductivity

low MP/BP

low solubility in liquids (water)

low electrical conductivity

low heat conductivity

good insulator

method: a particular procedure to complete something

Conductivity:
Using a multi meter to test electrical conductivity

Ability of thermal conductivity:
place item on a heat place or heat source, using a thermometer or a thermal heat gun, after a period of time. Measure the surface of test pieces record data for heat as a function of time.

Solubility test
Chose different solvents water (polar)add item and stir, record weather it dissolved into solvents or not.


classify substance if dissolved or not. soluable in water: presecnce of ionic or polar covalent bonds, insoublable indicates prescence of non polar covalent bonds

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