The atomic structure

 is the symbol of aluminium.

(a) Determine the number of neutron of aluminium.
(b) Write the electron arrangement of aluminium atom.

(c) Write the valence electron of aluminium

Answer:
a) 27 - 13 = 14
b) 2.8.3
c) 3

Experiment-to determine the melting point of naphthalene

Diagram show the apparatus to determine the melting point of naphthalene.

(heating process)

Experiment-to determine the freezing point of naphthalene

Diagram show the apparatus to determine the freezing point of naphthalene.

Make sure you label the apparatus.

Experiment-to determine the melting point and freezing point of naphthalene

Matter

Element: (satu jenis shj)
sodium, Na; copper,Cu; hydrogen, H2; oxygen, O2 ;

Compound: (dua atau lebih jenis)
water, H2O; carbon dioxide, CO2; sodium chloride, NaCl

Typer of particles:
Atom: (satu sahaja)
sodium, Na; copper,Cu

Molecule: (dua atau lebih)
hydrogen, H2; oxygen, O2 ; water, H2O; carbon dioxide, CO2

Ion: (positive ion + negative ion)
sodium chloride, NaCl

Proton number and nucleon number

Proton number (atomic number)   =   number of protons in its atom

Nucleon number (mass number)    =   total number of proton and number of neutron in its atom

Diffusion of bromine gas in gas jar

Bromine is made up of tiny and discrete particles.
The bromine particles move quickly in between the air particles,
from high concentration area to low concentration area

Isotope

Atom of the same element with same number of proton and different number of nucleon.
Examples:
Carbon-14 = to determine the age of bones
Cobalt-60 = to use for the treatment of cancer