Chemistry 1 from 3
Chapter 1 MATTER
TYPES OF MIXTURES- Solid-solid Mixture
Examples include; Beans and corn,
Method of separation; Hand picking
- Solid-liquid Mixture
Examples include; Rice and soup
Method of separation; sedimentation, draining or damming
- Liquid-liquid Mixture
Examples include; oil and water
Method of separation; Fractional distillation, simple distillation.
- Liquid-gas Mixture
Examples include; Juice and gas (top ananas)
Method of separation; Opening the container in which the combination has been locked for it to evaporate.
Change of States
- Solid to liquid: melting or fusion.
- Liquid to solid: Freezing or solidification.
- Liquid to gas: Evaporation.
- Gas to liquid: Condensation or liquefaction.
- Solid to gas: Sublimation.
- Gas to solid: Deposition.
ATOMIC STRUCTURE
An atom is the smallest indivisible particle of an element that takes part in a chemical reaction. An atom is made up of two parts:
- Nucleus and
- Shell(s)
An atom is made of three parts:
- Protons,
- Electrons and
- Neutrons
Differences between a Physical Change and a Chemical Change
|
Physical Change |
Chemical Change |
|
No new substances are formed |
New substances are formed |
|
It is easily reversible |
It is not easily reversible |
|
There is no change in mass |
There is redistribution of mass |
|
The chemical properties do not change |
Chemical properties do change |
Properties of Protons, Neutrons and Electrons
|
Particle |
Mass |
Charge |
Location |
Contribution |
Discoverer |
|
|
Proton |
1 |
+1 |
nucleus |
Contributes to the mass of atoms tells us the atomic number |
Ruther ford 1920 |
|
|
Neutron |
1 |
0 |
nucleus |
Contributes to mass of an atom |
Chadwick in 1932 |
|
|
Electron |
11840(negligible) |
-1 |
Shells (orbitals) |
Determines the chemical properties am of an atom |
J.J Thompson in 1897 |
|
- The forces that hold protons and electrons together are called electrostatic force.
- When an atom has more protons than electrons or more electrons than protons it is said to be charged.
- It determines the nucleus of an atom position of element on periodic table.
- Atomic number = number of proton.
- Mass number = number of protons and neutrons in the nucleus of an atom.
- Neutron number = mass number - proton number
zAX
A= mass number , Z= atomic number , A-=neutron number