Unit 2 review ©

  1. Look at the models of the atom that have progressed over time, which scientist.

Thought it looked like a solid ball? ______

Thought it was a positive background with negative particles stuck in it? ______

Discovered the nucleus and thought the atom was mostly empty space? ______

Determined that electrons are arranged in specific energy fields? ______

Discovered the neutron? ______

What does the current model of the atom look like? ______

  1. What are the 3 particles an atom is made of? What is the electric charge of each? Mass of each?

______

______

  1. Look at the periodic table.
  2. For the element oxygen (O) find the: # of protons # of neutrons and # electrons for an electrically neutral atom.

# protons______

# neutrons______

# electrons ______

  1. Draw the Bohr diagramfor oxygen (if you don’t remember what a Bohr diagram is. Look back at the first question) (remember the 2-8-8 rule)
  1. If you added a neutron to this atom what would it be called? ______
  1. How would the atom become an oxygen ion? ______
  1. Is an oxygen ion positive or negative? Why? ______

______

  1. Could the atom have 9 protons and still be oxygen? Explain why or why not. ______

______

______

Sulfur has 3 isotopes. Use the periodic table to find the Isotopic mass and % abundance of Sulfur-33

Isotopic Mass / % Abundance
Sulfur-32 / 31.972 / 94.93
Sulfur-33 / ??????????? / ??????????
Sulfur-34 / 33.967 / 4.29
  1. Look at the periodic table again.
  2. What are the all elements on the left of the zigzag line? ______
  3. What are the elements on the right? ______
  4. What are the elements that touch the line? ______

What are the general properties of metals?

What are the general properties of non-metals?

What are the general properties of the main families? Which elements belong in each?

Alkali

Alkaline Earth

Halogen

Noble Gasses

What type of bonds are formed between metals and non-metals?______

What type of bonds are formed between non-metals and non-metals? ______

When sodium bonds ionically with chlorine 1 electron is transferred. Explain why. ______

______

What is an element? ______

What is a compound? ______

What is a mixture? ______

Which of the above can you separate by physical means? (filtering, using your hands, using magnet, etc…)

What is a solution? ______

What is a saturated solution? ______

What is an unsaturated solution? ______

What is the formula to calculate the concentration of a solution?

An experiment requires a total of 600 mL solution of methyl alcohol and water with a 45% concentration. What volume of methyl alcohol should be used?

Name the physical properties of substances.

Name the chemical properties of substances.

Water freezing is what type of change? Physical or chemical? Why? ______

______

Paper burning is what type of change? Physical or chemical Why? ______

______

What does a chemical change result in? ______

What does the law of conservation of mass say? ______

______

Balance the following:

Cl2 + NaBr ---> NaCl + Br2 H2 + N2 --- NH3

Na + Br2 ---NaBr CuCl2 + H2S --- CuS + HCl

What are the 4 states of matter? ______

In which do the molecules move the fastest? ______

What are the 6 phase changes? List which phase is changing to which for each.

Draw a phase change diagram for water: Label the phases and phase changes

What does density measure? ______

What is the formula for density? ______