ChemistryChemistry

Ions

Red and Green are opposites

Assume red and green cancel each other

net color = neutral

take away one red net color = 1 green

take away two red net color = 2 green

net color ? = 2 green

net color = 2 redAdd two red

green is trapped inside.Only red ballscan be added ortaken away…

in this arrangement…

color = 2 greenTake away two red

color = 1 redNet colour?

color = ?

3 red

color = ?

3 green

Subatomic Particles (Table 2.1)

Particle Mass

(g) Relative

Mass (amu) Charge

Electron (e-) 9.1 x 10-28 0 -1

Proton (p+) 1.67 x 10-24 1 +1

Neutron (n0) 1.67 x 10-24 1 0

++

++

+

the particlesthat make up atomshave eitherpositive or negative charge

In order to understandwhat ions are,we need to know that…

++

++

+

Positive and negative are opposites

they cancel each other out

Therefore, the net charge = zero

+

the positive (+) particle is called a

proton

the negative (-) particle is called an

electron

++

++

+

In an atom,protons ( ) are inthe centerand electrons ( )are on the outside

+

only electrons ( )can be addedor taken away

++

++

+

This is an atom with5 electrons and

5 protons

the atom is neutral net charge = zero

Equal “+” and

“-” charges

++

++

+

5 (-) and 5 (+) = zero charge (neutral)

++

++

+

= -1 (one minus)charge = ?

++

++

+

+2 (two plus)

charge = ?

WHEN REMOVING ELECTRONS

THE RESULTING CHARGE IS POSITIVE

neutral 1+

We are now LESS negative = MORE positive

THE RESULTING CHARGE IS NEGATIVE

neutral 2

WHEN ADDING ELECTRONS

We are now MORE negative = LESS positive

An atom with positive or negative charge

is called andrum roll

ION

Atoms without charge are called ATOMS

Atoms with positive or negative charge

are called IONS

Notice that ONLY the number of e- changes

The number of protons in anAtom NEVER changes –

They are trapped inside the nucleus

(Only electrons are added or subtracted)

An ion is an atom, or group of atoms, that has a net positive or negative charge.

cation ion with a positive charge. If a neutral atom loses one or more electrons it becomes a cation.

anion ion with a negative charge. If a neutral atom gains one or more electrons it becomes an anion.

Na 11 protons11 electrons Na+ 11 protons

10 electrons

Cl 17 protons17 electrons Cl- 17 protons

18 electrons

How do we know what charge our ion will

have????

We need to look at our Bohr-Rutherford Diagrams

-Most atoms on their own will form ions to complete their outer orbit (energy level)

Fluorine

Put simply - An atom wants to have a full outer orbit (2 for He, 8 for others). To do this they can either:-Lose 1 or more electrons (cation +)

-Loses outer orbit

Or

-Gain 1 or more electrons (anion -)-Fills outer orbit

How do you know which it will be?

It will be whatever is easier

-If it has 1 valence electron it will lose 1 and lose its outer orbit easier to lose 1 than gain 7

- If it has 7 valence electrons it will gain 1 to get 8 easier to gain 1 then lose 7!

IonsWe will only be dealing with groups:

1, 2, 13, 15, 16, 17

**Generally speaking, elements on the left (metals and metalloids) will lose e’ to form cations while elements on the right (non-metals) will gain e’ to form anions **

The shortcut!-Look at your periodic table-Ignore the transition metals, the carbon family and Boron-Overtop of the groups write how many electrons they will lose or gain to have a complete outer orbit 8 (or 2 for H and He)-Write whether it will lose the electrons (+) or gain (-)

**Remember, gaining electrons gives a “-” charge**-Example, Be – will lose two to shed its outer orbit = Be+2+

1+2

+3

-3 -2 -1

10 n0

How to properly draw ions

-• Draw Bohr-Rutherford Diagram• Include protons and neutrons in nucleus• Put square brackets around diagram• Place charge top right

Naming IonsPositive Ions – The name is the same as the name of the element followed by ione.g. Na+ = Sodium Ion

Negative Ions – The name is determined by removing the end and adding idee.g. Oxygen Ion = Oxide ion, Phosphorus Ion = Phosphide ion

Multivalent Ions

-Mostly involves transition metals (Copper, Iron) but also includes Tin (Sn) as well as a few others

-Multiple charges are possible therefore you need more information

Multivalent Ions – Write the name given the symbol

Multivalent Ions – Write the name and Roman Numerals-If you are given the Symbol with the charge you can write the name but you must include the roman numeral which represents the charge - E.g. Cu4+ = Copper (IV) ion- Ni3+ = Nickel (III) ion

-** I=1, II=2, III=3, IV=4, V=5, VI=6, VII=7

Multivalent Ions – Write the Symbol given the name

-The Roman Numeral in the name represents the charge on the ion

-E.g. Lead (IV) ion = Pb4+

-Cobalt (II) ion= Co2+

-**Multivalent Ions will always be positive because they are metals

E T C E T E R A

Ions make up the salt you put on your eggs inthe morning

Ions are required for your brain to function(ions allow you to see and understand this presentation)

Ions keep you alive by controlling your pH

Ions allow you to move (are also called electrolytesas seen in all sports drinks)