DIFFERENCES BETWEEN BOILING &
EVAPORATION:
BOILING
EVAPORATION
When a liquid boils,
ALL the particles in the liquid have
enough energy to become a gas​
When a liquid evaporates, only
the particles on the surface of
the liquid change into a gas​
Boiling occurs at
a FIXED or DEFINITE temperature,
called the BOILING POINT
Evaporation can
occur at ANY temperature
It is a quick process
It is a slow process​
2.1 Properties of substances
Important definitions
1. Melting point: The temperature at which a solid becomes a liquid. Unit for melting
point is oC.
2. Boiling point: The temperature at which particles throughout a liquid have enough
energy to change to a gas. Unit for boiling point is oC.
3. Property: A property is something about a substance that allows us to tell it apart
from other substances. Melting and boiling points are examples of such a property.
4. Independent variable: Variable that is changed or manipulated in an experiment
5. Dependent variable: Variable that is measured in an experiment
6. Control variable: Variable that is kept the same throughout in an experiment
7. X-axis: The horizontal axis of a graph. The independent variable is plotted along
this axis.
8. Y-axis: The vertical axis of a graph. The dependent variable is plotted along this
axis.
2.2 Thermal and electrical conductors
Important definitions
1. Conductors: Any substance or material that allows heat or electricity to pass
through it.
2. Conduction: The transfer of heat or electrical energy from one object to
another.
3. Electrical conductors: Materials and substances that conduct electricity well
4. Thermal conductors: Materials and substances that conduct heat well
5. Insulators: Any substance or material that does not allow heat or electricity
to pass through it.
2.3 Reversible changes
Important definitions
1. Reversible: Can be changed back to the way it was before
2. Irreversible: Cannot be changed back to the way it was before
3. Physical change: Any change that does not change a substance into a
different substance.
4. Solute: The substance that dissolves in a solution, e.g. salt or sugar
5. Solvent: The substance in which the solute dissolves, in a solution, e.g.
water
6. Rate: How fast something happens
7. Uniform: To look the same throughout
2.3 Reversible changes
Solute, solvent, solution
States of matter
There are 3 states of matter:
1. Solid
2. Liquid
3. Gas
States of matter
Types of Scientific Enquiry
There are 5 types of scientific enquiry:
1. Research: looking for answers to a scientific question using secondary sources,
such as books, the internet or videos.
2. Fair testing: Wherein we change one factor or variable and keep all the others
same, to try an answer a scientific question. It comprises of the dependent,
independent and control variables.
3. Observing over time: By observing changes that may take place right away or
over a long period of time
4. Identifying and classifying: By recognizing features that are similar to one
another or different from one another, and naming and grouping them.
5. Pattern seeking: By observing, recording and analyzing data to identify a
relationship or trend, between two or more things.
Types of Scientific Enquiry