Answer the following questions-

Q23. Find the element that would need one more electron to fill its second electron shell. Q24. Find the element with two electrons in its third electron shell.

Q5. Assuming all measurements are under normal conditions (referred to as STP or Standard Temperature and Pressure). Search and find the following information

• What is the density of 100.0 grams of sodium? What is the density of 128 kg of sodium?
• What is the density of 100.0 grams of silver? What is the density of 128 kg of silver?
• What does this tell you about the correlation of density to the quantity you have of a substance?

Q6. Please answer all parts to this question AND show your work.

1. The density of copper is 8.94 g/cm³. What is the mass of a rectangular sheet of copper is 10 cm wide, 45 cm long, and 0.2 cm thick?
2. A sample of aluminum metal has a mass of 8.4 g. The volume of the sample is 3.1 cm³. Calculate the density of the aluminum.
3. What is the density of an 84.7 g sample of an unknown substance if the sample occupies 49.6 cm³?
4. If an liquid has a density of 1.67 g/cm³ , what is the volume of 45 g of the liquid?

answer the following questions:

Q15. Which solid nonmetal with an atomic mass below 40 needs two electrons in its outer orbital to complete its octet? Q16. Which metal is molten or can melt on a hot day?

Q2. Describe the covalent bonding in each of the following molecules. You may use a verbal description or Electron Dot Diagrams for your description.

1. H₂O

2.NH₃

3. Cl₂

4. HBr

Q4. what is an example of an ionic compound with a 1:2 ratio? Q5. Illustrate the following ionic substances. You can do this as electron dot diagrams, verbal descriptions, or pictorial diagrams.

1.LiCl

2. CaO

3.KBr

4. SrI₂

5. MgCl₂

Q1. For each of the following, predict the chemical formula of the binary ionic compound they form. Show all your steps as we did in the examples above (using either the method in examples 1&2 or the "criss-cross" method) and check to make sure the charges balance. Name each compound (some of the names are given).

1. lead (II) iodide
2. potassium and iodine
3. calcium and chlorine
4. lithium and oxygen
5. zinc with a +2 charge and oxygen
6. silver with a +1 charge and chlorine

Q2. Classify each of the following as an endothermic or exothermic process and explain your choice:

1. Melting ice
2. Water evaporating
3. When iron is oxidized and forms iron oxide (rust) it gives off heat.
4. The gas expands in the coils of an air conditioner making them cold to the touch.
5. The burning of a gasoline and air mixture in an automobile engine.

Q3. Provide your own examples, other than the ones given in this lesson, of an exothermic and an endothermic process and explain.

Q4. What is the balanced equation for the reaction of N₂ and H₂ to form NH₃? What type of reaction is this? Q5. Click on the "Separate Water" option button on the top right of the applet. Follow the same steps to balance this equation. What is the balanced equation for the reaction of "H₂O" to form "H₂" and "O₂"? What type of reaction is this? Q6. Click on the "Combust Methane" option button on the top right of the applet. Follow the same steps to balance this equation. What is the balanced equation for the reaction of "CH₄" with "O₂" to form "CO₂" and "H₂O"? What is the name of each of the compounds in the equation?

Q7. What is the balanced equation for the reaction of Al and O₂ to form Al₂O₃? What is the name of each of the compounds in this equation? What type of reaction is this?

Q9. Answer all parts of this question as they relate to the chemical equation:

Zn + 2 HCl ---> ZnCl₂ + H₂

1. What is the name of each compound in this equation?
2. What type of reaction is this?
3. Is this equation balanced? Show your work and explain why it is or is not balanced.

Q10. Answer all parts of this question as they relate to the chemical equation:

FeS + HCl ---> H₂S + FeCl₂

1. What is the name of each compound in this equation?
2. What type of reaction is this?
3. Is this equation balanced? Show your work and explain why it is or is not balanced.

Q1. Define each of the following terms.

1. homogeneous mixture
2. heterogeneous mixture
3. element
4. compound
5. pure substance
6. solution

Q2. List at least six methods, and explain each, that can be used to separate mixtures. Q3. Read each of the following descriptions/questions and identify each as an element, compound, heterogeneous mixture, or homogeneous mixture. Explain the reason for each choice.

1. Air
2. A stainless steel fork
3. Molten iron
4. Trail mix
5. Distilled water
6. Salt water

Q4. Mixtures can occur between all phases of matter. Give an example for each of the following mixtures:

1. Gas/gas
2. Gas/liquid
3. Liquid/liquid
4. Solid/liquid
5. Solid/solid

Q7. Describe two observable properties of acids and two observable properties of bases.

Q8. Find out the name of the acid which occurs in your stomach. What is the approximate pH in your stomach.

Q9. Find out the names of 3 acids and 3 bases that you will find around the home or in your foods. Q10. Identify each of the following as acidic, basic or neutral.

1. Lemon juice
2. Caustic soda
3. Battery Acid (sulfuric acid)
4. Borax
5. Milk of magnesia
6. Vinegar
7. HNO₃
8. HF
9. Vitamin C
10. Soap

Q11. For each part of this question a property of a solution is given. Based upon the listed property, identify each as an acidic or basic solution.

1. Turns blue litmus paper red.
2. Has a pH of 12.4 .
3. Feels slippery.
4. Has a tart or sour taste.
5. Turns red litmus paper blue.
6. Has a pH of 3.1 .
7. Reacts with active metals such as zinc and magnesium.

Q12. On a long conveyor belt in a recycling plant, a fine powder of a grounded mixture of aluminum cans, steel cans, soda cans, and milk jugs is moving along. What techniques will you use to separate all the different materials? Describe the techniques in detail and include the properties of the materials that you utilize to accomplish the separation. Q13. Find out which salts are normally present in tap water? Q14. Find out where the table salt in different parts of the world comes from. Describe at least three different methods of producing table salt and include regions where these methods are used. Q15. Find out what we mean by water hardness.