Atomic Structure and Bonding

What We Will Cover:

•Subatomic Particles

•Atomic Number

•Atomic Mass Unit Number and Calculations

•Electron Arrangement

•Bonding – Ionic and Covalent

Sub Atomic Particles

• Protons

• Neutrons

• Electrons

Protons

• Located in nucleus of atom

• Has a positive charge

• Number of Protons = Atomic Number

• Has 1 AMU in mass (Atomic Mass Unit)

+

+

+

Neutrons

• Located in nucleus of atom

• Has NO electrical charge

• Has mass of 1 amu

• Number of neutrons usually is equal to number of protons

Quiz – SubatomicParticles

1.The positive particle is the ___. 2.The negative particle is the ___. 3.The neutral particle is the ___. 4.The proton is the same as the __ number. 5.The two particles located inside the nucleus are the __ and the __. 6.Each of these particles have a mass of ___.

Electrons

• Located outside the nucleus of the atom

• Housed in Electrical Clouds, Shells, Orbits

• Has a negative charge• Does not have an amu

because of tiny size• Moves around the

nucleus in an orbit

Hydrogen

Atom

Electron

Cloud

Quick Quiz – Subatomic Particles(continued)

7. The electron ___ around the nucleus.

8. The ___ electrons are the outer ___ electrons and are involved in ___ bonding. 9.To find the number of neutrons in an atom you subtract the __ number from the ___ number.

Atomic Numbers

• Number used to arrange the Periodic Table

• Increase Left to Right

• Same as number of Protons or Electrons in a neutral atom

Atomic Mass

• The sum of the Protons and Neutrons in the nucleus.

• Also called Atomic Weight

Protons

+Neutrons

Atomic Weight

Electron Arrangement

• Electrons orbit the nucleus in Energy levels

• The first level (or cloud, or shell) contains up to 2 electrons

• The second level contains up to 8 electrons

• The third level contains up to 18 electrons

• 4th 32; 5th 50; 6th 72 max in shell

Electron Arrangement ctd.

• The electrons in the outermost shell (if it is not completely full) are available for bonding

• These electrons are called Valence Electrons

• Bonding is the chemical combining of 2 or more atoms.

Quick Quiz –Numbers, Electron Arrangement

10. The __ __ is used to arrange the periodic table as it increases from __ to __. 11. The atomic number is the same as the number of ___ . 12. The __ number is the sum of protons and neutrons inside the ___. 13. The outermost electrons are the __ electrons and they orbit the nucleus in __ levels. 14. Bonding is the ___________ combining of 2 or more ____________________

Bonding

• The process when 2 or more atoms combine chemically is known as Bonding

• The 2 we are learning today are

• Ionic Bonding

• Covalent Bonding

Ionic Bonding

• Electrons are either gained or lost by atom

• One atom is positive +, One is negative -

• Occurs between Metals and Nonmetals• Metals lose electrons• Nonmetals gain electrons• Very strong bond – usually solids - with

high melting temperatures

Sodium and Chlorine

Sodium – a soft grey highly flammable metal

Chlorine – a highly poisonous green gas

+

= (equals)

Table Salt

Lithium and Fluorine diagram shows Ionic Bonding in action

Common Ionic Bonds

• NaClSodium Chloride Table Salt

• CuSo4 Copper Sulfate Kills algae

• NaHCO3 Baking Soda Baking & Health

Quiz – BondingIonic

15. In ionic bonding electrons are either _ or _. 16. __ lose electrons and ___ gain electrons. 17. A positive ions has __ electrons and a negative ion has __ electrons. 18. __ bonds are strong, usually solid, and have __ melting and boiling points. 19.The magic number of valence electrons needed by all but two atoms is ___. 20.Name two common ionic bonds.

Covalent Bonding

• Electrons are shared between atoms (co)

• Neither atom has an electrical charge

• Forces between atoms are weak – have low boiling or melting points

• Usually are liquids or gasses

• If a solid is usually a crystal

Water

Methane

Common Covalent Bonds

• H2O Water

• CH4 Methane

• C3H8 Propane

Quick Quiz – BondingCovalent

21. In a covalent bond, electrons are ___. 22. Neither atom has a ___. 23. Intermolecular forces __ __ are weak. 24. Covalent bonds have ___ melting and ___ points. 25. Covalent bonds are usually found in these two states of matter. 26. Two common covalent compounds are __ and __.

Ionic – Gain or Lose Electrons

Covalent – Share Electrons