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Communicating With Children About Medicines

Atoms, Molecules and Ions

Atoms are the smallest particle of any element

Sub-atomic particle	Proton(p)	Neutron(n)	Electron(e)
Relative Mass	1	1	1/1840
Relative Charge	+1	0	1

Protons and neutrons are in the nucleus which is positively charged and contains most of the mass
Mass of electrons too small to be counted as part of the mass
atom is electrically neutral as the number of positively charged protons is equal to the number of negatively charged electrons

Periodic Table

Contains metals, non-metals and metalloids-have properties of both metals and non-metals
Atoms(Noble gases) in group 18 are stable due to having a Completely Filled Outermost Electron Shell (CFOES) and are inert and exist as single atoms
Have a duplet(2) or octet(8) electronic configuration
Will share, lose or gain valence electrons for atoms to attain a stable noble gas electronic configuration
Therefore, atoms may need to lose or gain electrons to become stable in which they become charged particles called ions
- Gains valence electrons>negative ions (anions)
- Loses valence electrons>positive ions (cations)

Chemical Compound of Ions

Positive ions attracts negative ions in which an ionic compound is formed and an ionic bond exists between them>electrostatic forces of attraction
Ions formed through transfer of valence electrons from metals to non-metals

Example:

Name of Ion	Name of atom before the ion is formed	Charge of Ion	Chemical Formula
Hydrogen	Hydrogen	+1	H+
Oxide	Oxygen	-2	O2-
Chloride	Chlorine	-1	Cl-

Transition Metals

Name of Ion	Name of atom before the ion is formed	Charge of ion	Chemical Formula
Copper(I)	Copper	+1	Cu+
Iron(II)	Iron	+2	Fe2+
Iron (III)	Iron	+3	Fe3+

Finding the Chemical Formula

Sodium Chloride

Formula of ions	Na+	Cl-
Charge	+1	-1
Simplest Ratio	1	1

Chemical Formula: NaCl

Magnesium Chloride

Formula of Ions	Mg2+	Cl-
Charge	+2	-1
Simplest ratio	2	2

Chemical Formula: MgCl 2

*To find the chemical formula, you criss-cross the formula of the ions and the simplest ratio of the combining ions

Polyatomic Ions

Two or more atoms chemically combined to form an ion

Example:

Name	Number of each type of atom	Charge	Formula of Ion
Hydroxide ion	1 oxygen atom and 1 hydrogen atom	-1	OH-
Sulfate ion	1 sulfur atom and 4 oxygen atoms	-2	SO4 2-
Ammonium ion	1 nitrogen atom and 4 hydrogen atoms	+1	NH4+

Molecules

Two or more elements chemically combined together
Molecule of an element is made up of the same type of atoms
Molecules of a compound is made up of two or more different types of atoms

Examples:

Molecule of an Element

Element	Chemical Formula	Number of atoms in molecule
Hydrogen (H)	H2	2
Oxygen (O)	O2	2
Nitrogen (N)	N2	2
Sulfur (S)	S8 or S	2
Fluorine (F)	F2	8
Chlorine (Cl)	Cl2	2
Bromine (Br)	Br2	2

Molecule of Compounds

Chemical Name	Number of each type of atom	Chemical Formula
Water	2 hydrogen atoms and 1 oxygen atom	H2O
Carbon dioxide	1 carbon atom and 2 oxygen atoms	CO2
Nitrogen dioxide	1 nitrogen atom and 2 oxygen atoms	NO2
Sulfur dioxide	1 sulfur atom and 2 oxygen atoms	SO2

Chemical Equations

Must be balanced
Number of atoms of each element before and after the reaction must be equal
Mass is conserved during a chemical reaction
Tips from a wise woman
- Use numbers like 2 and 3
- Always try to make odd numbers even
- Balance ‘H’ and ‘O’ last
- Go for LCM (lowest common multiple)
- Always check answer