19) For each of the following elements, identify the number of protons or electrons needed for an electrically neutral atom.
a. carbon: 6 protons, 6 electrons.
b. aluminum: 13 protons, 13 electrons.
c. lead: 82 protons, 82 electrons.
d. chlorine: 17 protons, 17 electrons.
20) Decide whether each of the following atoms is electrically neutral.
a. sulfur: 16 protons, 18 electrons. No.
b. iron: 26 protons, 24 electrons. No.
c. silver: 47 protons, 47 electrons. Yes.
d. iodine: 53 protons, 54 electrons. No.
21) Classify each of the following as an electrically neutral atom, an anion, or a cation.
a. O^2-: anion
b. Li: electrically neutral atom.
c. Cl: electrically neutral atom.
d. Ag+: cation.
e. Hg^2+: cation
22) For each particle in Question 32, indicate whether the electrical charge or lack of electrical charge was from a neutral atom gaining electrons, losing electrons, or neither.
a. O^2-: gaining electrons.
b. Li: neither.
c. Cl: neither.
d. Ag+: losing an electron.
e. Hg^2+: losing electrons.
23) Write the symbol and show the electrical charge (if any) on the following atoms or ions:
a. hydrogen with 1 proton and 1 electron: H
b. sodium with 11 protons and 10 electrons: Na+
c. chlorine with 17 protons and 18 electrons: Cl-
d. aluminum with 13 protons and 10 electrons: Al^3+
24) Write the name and formula for the ionic compound that can be formed from these cations and anions:
a. Potassium iodine: KI
b. Calcium sulfide: CaS
c. Iron(iii) bromide: Fe^3+(Br-)3: (Fe)(Br)3
d. Barium hydroxide: Ba^2+ + (OH-)2: (Ba)(OH)2
e. Ammonium phosphate: (NH4+)3 + PO4^3-: (NH4)3(PO4)
f. Aluminum oxide: (Al^3+)2 + (O^2-)3: (Al)2(O)3
Monday, June 20, 2011
Water Diary
Day 1 total water use: 546.1 L
Day 2 total water use: 2827.75 L
Day 3 total water use: 761.5 L
3 day total water use: 4135.35 L
Average daily water use: 1378.45 L
Average water use per person per day: 459.48333 L
A.7 #1-7, p.20-21
1) Calculate the total water volume (in liters) used by your household during the three days.
The total water volume used by my household during the three days is 4135.35 liters.
2) How much water (in liters) did one member of your household use, on average, in one day?
On average, one member of my household used 459.48333 liters of water in one day.
3) Compile the answers to Question 2 for all members of your class by creating a histogram.
4) What is the range of the average daily personal water use within your class?
The range is 734 liters.
5) Calculate the mean and median values for the class data. Which do you think is more representative of the data set- the mean or median value? That is, which is a better expression of central tendency for these data?
The mean, or average, is 446 liters. The median is 459 liters. The better expression of central tendency for these data is the mean. The mean is lower than the median. Since our data only shows one extremely high number for water use per person, it is more appropropriate to express a lower central tendency; a closer number to the rest of the values.
6) Compare your answer from Question 2 with the estimated average volume of water, which is 370 L, used daily by each person in the United States. What reasons can you propose to explain any difference between your value and the national average value?
Our class has a higher value than the US average of 370 liters used per person per day. Since we have a large range of 734 liters due to one household with a very high water use per person per day (950 L) and two households with very low water uses per person per day (216 L), our higher average than usual makes sense. Desipte this higer mean, one household in our class had an average per person per day of 363 L, closer to the nation's 370 L average value
7) Which is closer to the nation average (mean) for daily water use per person, your answer to Question 2 or the class average in Question 5? What reasons can you give to explain why that value is closer?
The class average, 446 liters, is closer than my answer to Question 2, (459.48333 liters), to the nation average of 370 L for daily water use per person. I feel as though the average per person in my household per day is higher because of my large garden. My garden is much larger than most, and therefore, uses a lot more water than standard-sized gardens. My garden uses over 2,076 L of water three times a week, with additional, unaccounted for hosing in between. This increases the the average value of water use in my house significantly, and makes it higher than both the class average of 446 L, and the nation average of 370 L per person per day.
The total water volume used by my household during the three days is 4135.35 liters.
2) How much water (in liters) did one member of your household use, on average, in one day?
On average, one member of my household used 459.48333 liters of water in one day.
3) Compile the answers to Question 2 for all members of your class by creating a histogram.
4) What is the range of the average daily personal water use within your class?
The range is 734 liters.
5) Calculate the mean and median values for the class data. Which do you think is more representative of the data set- the mean or median value? That is, which is a better expression of central tendency for these data?
The mean, or average, is 446 liters. The median is 459 liters. The better expression of central tendency for these data is the mean. The mean is lower than the median. Since our data only shows one extremely high number for water use per person, it is more appropropriate to express a lower central tendency; a closer number to the rest of the values.
6) Compare your answer from Question 2 with the estimated average volume of water, which is 370 L, used daily by each person in the United States. What reasons can you propose to explain any difference between your value and the national average value?
Our class has a higher value than the US average of 370 liters used per person per day. Since we have a large range of 734 liters due to one household with a very high water use per person per day (950 L) and two households with very low water uses per person per day (216 L), our higher average than usual makes sense. Desipte this higer mean, one household in our class had an average per person per day of 363 L, closer to the nation's 370 L average value
7) Which is closer to the nation average (mean) for daily water use per person, your answer to Question 2 or the class average in Question 5? What reasons can you give to explain why that value is closer?
The class average, 446 liters, is closer than my answer to Question 2, (459.48333 liters), to the nation average of 370 L for daily water use per person. I feel as though the average per person in my household per day is higher because of my large garden. My garden is much larger than most, and therefore, uses a lot more water than standard-sized gardens. My garden uses over 2,076 L of water three times a week, with additional, unaccounted for hosing in between. This increases the the average value of water use in my house significantly, and makes it higher than both the class average of 446 L, and the nation average of 370 L per person per day.
Sunday, June 19, 2011
Friday, June 17th Homework Assignment for Monday, June 20th.
ISBS, p. 50-52
13) See drawing.
14) Look at models.
a. Which models represent elements?
b. Which models represent compounds?
a. models i, ii, iv, and vi.
b. models iii and v.
15) What two pieces of information does a chemical formula provide?
A chemical formula provides each chemical substance (each element), and a subscript below each element representing how many atoms of each element is in one unit of the substance.
16) Name the elements and list the number of each atom indicated in the following substances:
a. phosphoric acid, H3PO4 (used in soft drinks)
b. sodium hydroxide, NaOH (found in some drain cleaners)
c. Sulfur dioxide, SO2 (an air pollutant)
a. Elements: Hydrogen, Phosphorus, and Oxygen. 3 Hydrogen atoms, 1 Phosphorus atoms, and 4 Oxygen atoms.
b. Elements: Sodium, Oxygen, Hydrogen. 1 Sodium atom, 1 Oxygen atom, and 1 Hydrogen atom.
c. Sulfur and Oxygen. 1 Sulfur atom and 2 Oxygen atoms.
17) See drawings.
18) Write chemical equations that represent the following word equations:
a. Baking soda (NaHCO3) reacts with hydrochloric acid (HCl) to produce sodium chloride, water, and carbon dioxide.
b. During respiration, one molecule of glucose, C6H12O6, combines with six molecules of oxygen gas to produce six molecules of carbon dioxide and six molecules of water.
a. NaHCO3 + Hcl → NaCl + H2O + CO2
b. C6H12O6 + O6 → 6 CO2 + 6 H2O
13) See drawing.
14) Look at models.
a. Which models represent elements?
b. Which models represent compounds?
a. models i, ii, iv, and vi.
b. models iii and v.
15) What two pieces of information does a chemical formula provide?
A chemical formula provides each chemical substance (each element), and a subscript below each element representing how many atoms of each element is in one unit of the substance.
16) Name the elements and list the number of each atom indicated in the following substances:
a. phosphoric acid, H3PO4 (used in soft drinks)
b. sodium hydroxide, NaOH (found in some drain cleaners)
c. Sulfur dioxide, SO2 (an air pollutant)
a. Elements: Hydrogen, Phosphorus, and Oxygen. 3 Hydrogen atoms, 1 Phosphorus atoms, and 4 Oxygen atoms.
b. Elements: Sodium, Oxygen, Hydrogen. 1 Sodium atom, 1 Oxygen atom, and 1 Hydrogen atom.
c. Sulfur and Oxygen. 1 Sulfur atom and 2 Oxygen atoms.
17) See drawings.
18) Write chemical equations that represent the following word equations:
a. Baking soda (NaHCO3) reacts with hydrochloric acid (HCl) to produce sodium chloride, water, and carbon dioxide.
b. During respiration, one molecule of glucose, C6H12O6, combines with six molecules of oxygen gas to produce six molecules of carbon dioxide and six molecules of water.
a. NaHCO3 + Hcl → NaCl + H2O + CO2
b. C6H12O6 + O6 → 6 CO2 + 6 H2O
Thursday, June 16, 2011
Thursday, June 16th Homework Assignment for Friday, June 17th.
Sketches for #1 and #3 (will also turn in a clear hard copy in class):
2) What kind of matter does the following model represent? Explain your answer.
This model represents a mixture of two two-atom compounds, with one compound having two atoms of one element, and the other compound having three atoms of one element. Since the compound with two atoms of one element, (probably H2O) floats above the other compound, this is a heterogeneous mixture and an example of suspension.
2) What kind of matter does the following model represent? Explain your answer.
This model represents a mixture of two two-atom compounds, with one compound having two atoms of one element, and the other compound having three atoms of one element. Since the compound with two atoms of one element, (probably H2O) floats above the other compound, this is a heterogeneous mixture and an example of suspension.
Wednesday, June 15, 2011
Unit I B.1-B.4 Vocabulary List
matter: anything that occupies space and has mass.
physical properties: properties that can be observed and measured without changing the chemical makeup of the substance.
density: the mass of material within a given volume. Water: 1g/mL, 1g/cm^3.
freezing/melting point (of water): 0°C or 32°F.
boiling point (of water): 100°C or 212°F.
aqueous solution: water-based solution.
surface tension: shows the strong intermolecular force that holds water molecules together.
mixture: when two or more substances combine and the substances retain their individual properties. The components of a mixture can be separated by physical means, such as filtration and adsorption.
heterogeneous mixture: composition is not the same, or uniform, throughout. (not evenly distributed).
suspension: solid particles are large enough to settle out or can be separated by using filtration.
Tyndall Effect: the scattering of light that indicates that small, solid particles, are still in the water.
collid: the small, solid particles that remain still in the water. Make liquid cloudy.
homogeneous mixture: a mixture that is uniform throughout. (evenly distributed).
solutions: homogeneous mixtures. (such as salt solution)
solute: salt in a salt solution.
solvent: water in a salt solution; dissolving agent.
particulate level: the level of atoms and molecules.
atoms: building blocks of matter. all matter is made of atoms.
element: matter that is made up of only one kind of atom.
compound: a substance that is composed of the atoms of two or more elements linked together chemically in certain fixed proportions.
chemical formulas: represent compounds.
substance: all elements and compounds. has a uniform and definite composition, as well as distinct properties.
molecule: the smallest unit of a molecular compound that retains the properties of that substance (smallest representation of the substance) ex: H2O molecule represents water.
chemical bonds: hold atoms of molecules together.
molecular compound: such as H2O
physical properties: properties that can be observed and measured without changing the chemical makeup of the substance.
density: the mass of material within a given volume. Water: 1g/mL, 1g/cm^3.
freezing/melting point (of water): 0°C or 32°F.
boiling point (of water): 100°C or 212°F.
aqueous solution: water-based solution.
surface tension: shows the strong intermolecular force that holds water molecules together.
mixture: when two or more substances combine and the substances retain their individual properties. The components of a mixture can be separated by physical means, such as filtration and adsorption.
heterogeneous mixture: composition is not the same, or uniform, throughout. (not evenly distributed).
suspension: solid particles are large enough to settle out or can be separated by using filtration.
Tyndall Effect: the scattering of light that indicates that small, solid particles, are still in the water.
collid: the small, solid particles that remain still in the water. Make liquid cloudy.
homogeneous mixture: a mixture that is uniform throughout. (evenly distributed).
solutions: homogeneous mixtures. (such as salt solution)
solute: salt in a salt solution.
solvent: water in a salt solution; dissolving agent.
particulate level: the level of atoms and molecules.
atoms: building blocks of matter. all matter is made of atoms.
element: matter that is made up of only one kind of atom.
compound: a substance that is composed of the atoms of two or more elements linked together chemically in certain fixed proportions.
chemical formulas: represent compounds.
substance: all elements and compounds. has a uniform and definite composition, as well as distinct properties.
molecule: the smallest unit of a molecular compound that retains the properties of that substance (smallest representation of the substance) ex: H2O molecule represents water.
chemical bonds: hold atoms of molecules together.
molecular compound: such as H2O
Wednesday, June 15th Homework Assignment for Thursday, June 16th.
Page 50:
1) What is a physical property?
A physical property is a property that can be observed and measured without changing the chemical makeup of the substance.
2) Identify three physical properties of water.
-Boiling point: 100°C or 212°F.
-Freezing point: 0°C or 32°F.
-Density: 1g/mL or 1g/cm^3
3) How does the density of solid water compare to the density of liquid water?
Since ice floats on the suface of liquid water, it is less dense.
4) Describe a setting where you might observe water as a solid, a liquid, and gas all at the same time.
One might observe water as a solid, a liquid, and a gas all at the same time in winter, at a waterfall in the mountains. The mountains surrounding the waterfall would be frozen, and as the powerful waterfall would crash onto the body of water below, many particles of water would rise into the air as water vapor, or gas. The cold mountains tend to be foggy as well, and fog is defined as a thick cloud of water droplets suspended in the atmosphere.
5) How are heterogeneous and homogeneous mixtures different?
In a heterogeneous mixture, the composition of it is not evenly distributed, or uniform, throughout. On the other hand, a homogeneous mixture is a mixture that is uniform throughout.
6) When gasoline and water are poured into the same container, they form two distinct layers. What do you need to know to predict which liquid will be on top?
In order to predict which liquid will be on top, it is necessary to know the densities of gasoline and water. The substance with the lower density would be on top.
7) Identify each of the following materials as a solution, a suspension, or a colloid.
a. A medicine accompanied by instructions to "shake before using"
b. Italian salad dressing
c. Mayonnaise.
d. A cola soft drink.
e. An oil-based paint.
f. Milk
a. A suspension
b. A suspension
c. A colloid
d. A solution
e. A suspension
f. A colloid
8) You notice beams of light passing into a darkened room through the blinds on a window. Does this demonstrate that air in the room is a solution, a suspension, or a collid? Explain.
Just like the Tyndall Effect, the beam of light passing into a darkened room through the blinds on a window reflects that since the light shines all the way through the room, it shows that there are small particles present in the air. This means that the air in the room is a collid; these particles are too small to come out through a filter. Although air appears to be a homogeneous mixture, the Tyndall Effect done through natural light proves that it is a heterogeneous mixture.
9) Drawing: separate paper.
10) Suppose you have a clear, red liquid mixture. A beam of light is observed as it passes through the mixture. Over a period of time, no particles settle to the bottom of the container. Classify this mixture as a solution, a collid, or a suspension, and provide evidence to justify your choice.
This mixture is a collid. Since with the Tyndall Effect, the beam of light passes through the mixture, it is evident that the particles within the mixture are small, but not actually part of the mixture. Therefore, this mixture can not be a solution. Furthermore, since over a period of time, no particles settle to the bottom of the container, the mixture is not a suspension.
11) Define the term substance and give two examples.
A substance is an element or compound with a uniform and definite composition, as well as distinct properties. The smallest substance is a molecule, which is composed of atoms that are held together by chemical bonds. Two examples of substances are water, H2O, and ammonia, NH3.
12) Classify each of the following substances as an element or a compound.
a. CO
b. Co
c. HCl
d. Mg
e. NaHCO3
f. NO
g. I2
a. Compound
b. Element
c. Compound
d. Element
e. Compound
f. Compound
g. Compound
1) What is a physical property?
A physical property is a property that can be observed and measured without changing the chemical makeup of the substance.
2) Identify three physical properties of water.
-Boiling point: 100°C or 212°F.
-Freezing point: 0°C or 32°F.
-Density: 1g/mL or 1g/cm^3
3) How does the density of solid water compare to the density of liquid water?
Since ice floats on the suface of liquid water, it is less dense.
4) Describe a setting where you might observe water as a solid, a liquid, and gas all at the same time.
One might observe water as a solid, a liquid, and a gas all at the same time in winter, at a waterfall in the mountains. The mountains surrounding the waterfall would be frozen, and as the powerful waterfall would crash onto the body of water below, many particles of water would rise into the air as water vapor, or gas. The cold mountains tend to be foggy as well, and fog is defined as a thick cloud of water droplets suspended in the atmosphere.
5) How are heterogeneous and homogeneous mixtures different?
In a heterogeneous mixture, the composition of it is not evenly distributed, or uniform, throughout. On the other hand, a homogeneous mixture is a mixture that is uniform throughout.
6) When gasoline and water are poured into the same container, they form two distinct layers. What do you need to know to predict which liquid will be on top?
In order to predict which liquid will be on top, it is necessary to know the densities of gasoline and water. The substance with the lower density would be on top.
7) Identify each of the following materials as a solution, a suspension, or a colloid.
a. A medicine accompanied by instructions to "shake before using"
b. Italian salad dressing
c. Mayonnaise.
d. A cola soft drink.
e. An oil-based paint.
f. Milk
a. A suspension
b. A suspension
c. A colloid
d. A solution
e. A suspension
f. A colloid
8) You notice beams of light passing into a darkened room through the blinds on a window. Does this demonstrate that air in the room is a solution, a suspension, or a collid? Explain.
Just like the Tyndall Effect, the beam of light passing into a darkened room through the blinds on a window reflects that since the light shines all the way through the room, it shows that there are small particles present in the air. This means that the air in the room is a collid; these particles are too small to come out through a filter. Although air appears to be a homogeneous mixture, the Tyndall Effect done through natural light proves that it is a heterogeneous mixture.
9) Drawing: separate paper.
10) Suppose you have a clear, red liquid mixture. A beam of light is observed as it passes through the mixture. Over a period of time, no particles settle to the bottom of the container. Classify this mixture as a solution, a collid, or a suspension, and provide evidence to justify your choice.
This mixture is a collid. Since with the Tyndall Effect, the beam of light passes through the mixture, it is evident that the particles within the mixture are small, but not actually part of the mixture. Therefore, this mixture can not be a solution. Furthermore, since over a period of time, no particles settle to the bottom of the container, the mixture is not a suspension.
11) Define the term substance and give two examples.
A substance is an element or compound with a uniform and definite composition, as well as distinct properties. The smallest substance is a molecule, which is composed of atoms that are held together by chemical bonds. Two examples of substances are water, H2O, and ammonia, NH3.
12) Classify each of the following substances as an element or a compound.
a. CO
b. Co
c. HCl
d. Mg
e. NaHCO3
f. NO
g. I2
a. Compound
b. Element
c. Compound
d. Element
e. Compound
f. Compound
g. Compound
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