1. Chemistry Review

2. Proton positively charged part of an atom found in the nucleus
has mass
constant in every atom of an element
Ex: every atom of oxygen has 8 protons

3. Neutron part of an atom that has no charge found in the nucleus
has mass
may be different in different atoms of the same element
Ex: an atom of carbon may have 6, 7, or 8 neutrons

4. Electron negatively charged part of an atom
found outside of the nucleus
has little to no mass
may change in number when an atom interacts with other atoms
Ex: sodium (Na) normally has 11 electrons but often loses 1

5. Ion
an atom that has lost or gained 1 or more electrons and now has a charge
lose electron = positive ion
gain electron = negative ion

6. Ion

7. Ion

8. Isotope atoms of the same element with different numbers of neutrons
does not affect how the atom reacts with other atoms

9. Ionic Bonds attraction connecting atoms of oppositely charged ions
bonds metals to nonmetals

10. Metals vs. Nonmetals

11. Ionic Bonds attraction connecting atoms of oppositely charged ions
bonds metals to nonmetals
one atom gives up 1 or more electrons to another atom

12. Ionic Bonds

13. Ionic Bonds attraction connecting atoms of oppositely charged ions
bonds metals to nonmetals
one atom gives up 1 or more electrons to another atom
form crystal lattices – patterned structures of repeating ions

14. Crystal Lattice

15. Ionic Substances
substances made of oppositely charged ions held together by ionic bonds
ex: table salt, rock (road) salt

16. Covalent Bonds
attraction connecting atoms that share 1 or more electrons
bonds nonmetals together
form molecules – individual groups of atoms

17. Carbon Dioxide Molecules

18. Covalent Bonds
attraction connecting atoms that share 1 or more electrons
bonds nonmetals together
form molecules – individual groups of atoms
the electrons are not always shared equally

19. Molecules in Air (nitrogen [N2], oxygen [O2], water [H2O], and carbon dioxide [CO2])

20. What is the difference between a crystal lattice and a molecule?
Crystal Lattice Sodium chloride NaCl
Molecule Carbon Dioxide CO2

21. What is the difference between a crystal lattice and a molecule?
In a crystal lattice, ions are interconnected as a part of a repeating pattern.
does not have a constant number of atoms
however, the ratio is always the same
Ex: A TINY piece of salt may have 1,000 sodium atoms and 1,000 chlorine atoms. Another SLIGHTLY BIGGER piece of salt may have 1,500 sodium atoms and 1,500 chlorine atoms. In both pieces, the ratio of sodium atoms to chlorine atoms is 1-to-1.

22. What is the difference between a crystal lattice and a molecule?
In a molecule, each group of atoms is only connected to the other atoms in that molecule.
the number of atoms of each element is constant
Ex: Carbon dioxide molecules are ALWAYS made of 1 carbon atoms and 2 oxygen atoms.

23. What is the difference between a crystal lattice and a molecule?
Crystal Lattice Sodium chloride NaCl
Molecule Carbon Dioxide CO2

24. Nonpolar Substances
substances held together by covalent bonds with equally shared electrons
no charged ends of the molecule
ex: methane, vegetable oil

25. Polar Substances
substances held together by covalent bonds with unequally shared electrons
unequal sharing causes the molecule to have charged ends
ex: water, sugar

26. What is the difference between a polar molecule and a nonpolar molecule?

27. What is the difference between a polar molecule and a nonpolar molecule?
Nonpolar molecules do NOT have charged ends.
Polar molecules HAVE charged ends.