form 4 chapter 2

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

NanoKids

FAME !!

Kinetic Theory of Matter

State Solid Liquid Gas

Arrangement

Movement Vibrate and Rotate and FIXED position

Packed closely but no in order

Very far from one another in random arrangement

Forces of Attraction Strong Medium Weak

Energy 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 needs energy !

Bond breaking: Absorb EnergyBond formation: Release Energy

Bond formation

Bond formationReleases

Heat into water

BUT….Water

ReleasesHeat into surroundings