Chapter 2 Matter
Atoms• Smallest particle of an element
Molecules• Two or more atoms bonded together COVALENTLY
Ion• Positively charged or negatively charged
Elements• Consists of only one atoms
Sulphur is an element !
• Consists of ALL the same ATOMS• All S atoms
How do we know ?• Atomic Force Microscopy (AFM)
Diamond• Consists of ALL the same ATOMS• All C atoms
Compounds• Consists of only two or more different atoms BONDED CHEMICALLY TOGETHER
Sodium Chloride (NaCl)
How do we know ?• Surface Electron Tunneling Microscope
• NaCl a compound !
Sulphur hexafluoride• Contains S and F
Kinetic Theory of Matter FAME !!
State Solid Liquid GasArrangementMovement Vibrate and Rotate Packed closely but no Very far from one and FIXED position in order another in random arrangementForces of Attraction Strong Medium WeakEnergy Content Low Medium High
Rates of Diffusion
Napthalene• Has Van Der Waals attraction
A to B• Solid temperature increase
B to C• Energy absorbed used to break bonds• Breaking bonds needs ENERGY !
C to D• Liquid temperature increase
D to E• Boiling !!!
E to F• Gas temperature increase
Bond formation• Bond formation needs energy !Bond breaking: Absorb EnergyBond formation: Release Energy
Bond formation ReleasesHeat into water
BUT…. Water ReleasesHeat into surroundings