Physical ScienceUNIT 3

Why do they stay atoms together?

Ionic- opposite charges attract

Covalent- sharing the electrons

Which do you think is stronger?

Ionic Bonds

Why do atoms lose or gain electrons?

Searching for the Happy 8 = 8 valence electron = stable electron configuration

Ionic bonds – transfer electrons

Me Myself and I(onic) – you take or give based on your preference

Bond between ions because of the electron transfer

Na = 1A gives 1e = Na+

F = 7A takes 1e = F-

Metals Nonmetals

Periodic Table

lets us be Fortune Tellers

What will bond between Ca and Cl look like?

Ca – Calcium – 2A – 2 electrons in outer valence

Cl – Chlorine – 7A – 7 electrons in outer valence

Ca – will give up 2 electrons = Ca 2+

Cl – will take 1 electron = Cl -

This swap isn’t a direct give and take.

Think of it like a puzzle

We get CaCl2 a = 2 Cl atoms for 1 Ca atom

A trick…

Ca 2++ Cl -

You can tell the formula by moving the charges to the subscripts

Ca 2++ Cl -

Ca1Cl2

Final Formula is CaCl2

Covalent Bonds

Bond formed when two atoms equally share

one pair of electrons

Polar and Nonpolar

Between Nonmetals and Nonmetals

Atoms remain bonded due to the attraction of shared electrons and the protons in the nucleus of each atom

Polar Molecules

Polar molecules attraction is higher

than nonpolar molecules

Higher boiling points

High surface tension

Increase in viscosity

slightly positive is attracted to slightly

negative of other molecules

Polyatomic Ions

Ionic Compounds – formula of compound describes the ratio of

the ions in the compound

Binary Ionic Compounds – made up of only two elements What is Name for BeCO3

Be2+ AND CO32-

Beryllium carbonate

What is formula for Calcium

Oxide?

Ca2+ O2-

CaO

Fe Man

Which was your favorite Iron Man?

Ion Names can also be specified by charge of the ion

Uses Roman Numerals I =1 II= 2

IV= ?

4 Fe(II)

= Fe 2+

Fe (III)

= Fe 3+

Remember your Greek

Molecular Compounds – named based on the

number of atoms in compound (covalent

bonds)

N2O4

Dinitrogen tetraoxide

You try - Cl2O7

Dichlorine heptoxide

Chlorine trifluoride

ClF3

Likely ions =

1A = 1+

2A = 2+

3A = 3+4A = not ions wants to find 4e

5A = 3-

6A = 2-

7A = 1-

8A = noble – leave us

alone

Not all elements in groups have ionic form – just used to predict

Polymers

Organic must have C-H bonds

Take good notes for Polymer Quiz

Write down the type of polymer and common uses and if it is synthetic (man made)

or naturally occurring.