1st Six Weeks Review

Chemistry

1. What are the 4 parts of Dalton’s Atomic Theory?

All matter is made up of atoms Atoms cannot be divided Atoms combine in whole # ratios (1:2, 2:3,

etc) to form compounds Compounds react to form new substances

during reactions

Discovered the Electron Used Cathode Ray tube experiment

2. Describe J.J. Thompson’s contribution to atomic theory and find a picture to illustrate it.

3. Describe Ernest Rutherford’s contribution to atomic theory and find a picture to illustrate it.

Discovered the nucleus Used the gold foil experiment – shooting

alpha particles at gold foil- some particles went through, some bounced off in all directions.

Proposed the planetary model of the atom Described Electron energy levels

4. Describe Niels Bohr’s contribution to atomic theory and find a picture to illustrate it.

Discovered the proton Particles going opposite electrons in cathode

ray tube.

5. Describe Eugene Goldstein’s contribution to atomic theory find a picture to illustrate it.

Discovered Neutrons

6. Describe James Chadwick’s contribution to atomic theory find a picture to illustrate it.

Proposed the Quantum Mechanical Model Orbitals predict location of electrons Electrons in energy levels Currently accepted atom model

7. Describe Erwin Schrodinger contribution to atomic theory find a picture to illustrate it.

8. Find a picture & 3 statements that describe a proton.

Positive charge Mass = 1 amu or 1.67 x 10-24g Found in the nucleus

Neutral charge Mass = 1 amu or 1.67 x 10-24g Found in the nucleus

9. Find a picture & 3 statements that describe a neutron.

Negative charge Mass = .0005 amu or 1.4 x 10-28g Moving rapidly around nucleus

10. Find a picture & 3 statements that describe an electron.

11. True or False: The nucleus contains most of the atom’s volume.

False!

The nucleus contains most of the atoms mass.

The electron cloud contains most of the atoms volume.

12. Illustrate an element square from the periodic table & label the information it provides.

13. True or False: Most of the volume of an atom is occupied by the electron cloud.

True!

14. A neutral carbon atom has how many protons, neutrons & electrons?

Protons = 6 Neutrons = 6 Electrons = 6 Total subatomic particles = ?

15. Magnesium is classified which of the following: solution, alloy, mixture or pure substance?

Pure substance!

16. What is an isotope?

Isotope is atom of the same element that has the same # of protons, but a different # of neutrons

17. What are the three isotopes of hydrogen? How many protons, neutrons & electrons does each one have?

Protium Deuterium Tritium

Protons 1 1 1

Neutrons 0 1 2

Electrons 1 1 1

Atomic Mass 1 amu 2 amu 3 amu

18. For the isotope Nitrogen-15, how many subatomic particles are present?(protons, neutrons, & electrons)

Total = 21particles

Atomic # = 7 (7 p, 7e-) Atomic mass = 14 (14-7 = 7 neutrons)

19. Potassium has an atomic number 19 and an atomic mass of 39. How many protons, neutrons and electrons does it have?

Protons = 19 Electrons = 19 Neutrons = 39 – 19 = 20

20. What is average atomic mass? How do you calculate it?

Weighted average of the naturally occuring isotopes of that element.

To calculate

1. Convert % to decimal

2. Multiply decimal by mass of isotope

3. Add numbers to complete average

21. What is the average atomic mass of silver?

.5186 x 106.9amu = 55.438

.4814 x 108.9amu = 52.424

 107.9 amu

Isotope Name

Isotope Mass (amu)

Percentage

Silver-107 106.90509 51.86

Silver-109 108.90470 48.14

Extra Practice: http://www.algebralab.org/practice/practice.aspx?file=

algebra_averageatomicmass.xml

22. Classify each of the following as an element, compound or mixture:

Sulfur - Element Salad oil - Mixture Newspaper - Mixture Orange - Mixture MgCl2 - Compound Cardboard - Mixture Apple juice - Mixture

23. What is density and how do you calculate it?

Density is the amount of matter in a given volume of substance.

m m D = V m = D*V V = D

24. Visit the following site:http://www.explorelearning.com/

Type “Density” in the Search Bar. Click on “Density Laboratory.” Click on “Gizmo” above the picture. Move objects onto the scale & into the

cylinder & calculate the density to predict if the object will sink or float.

25. Give 4 examples and a picture of physical changes.

Cutting Mixing Molding Evaporating Distillation Freezing Condensing

Burning Exploding Neutralizing Corroding Rusting

26. Give 4 examples and a picture of chemical changes.

Draw lines to match the following:

1. Electron a. neutral particle w/mass of 1.67 x 10-24 g2. Proton b. – particle w/ mass of 9.11 x 10-28 g3. Neutron c. + particle w/ mass of 1.67 x 10-24 g 4. Heterogeneous d. sample with uniform & definite

composition5. Homogeneous e. physical blend of 2 or more substances6. Mixture f. uniform mixture7. Element g. substance that can be chemically

separated8. Compound h. simplest form of a substance9. Pure substance i. mixture that is not uniform throughout