1. define physical change physical changes occur when objects undergo a change that does not change...
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1. Define Physical Change
Physical changes occur when objects undergo a change
that does not change their
chemical nature.
2. Define Chemical Change
• A chemical change produces a new substance. Examples of chemical changes include combustion (burning), cooking an egg, rusting of an iron pan, and mixing hydrochloric acid and sodium hydroxide to make salt and water.
3. Define Physical property
• Physical properties can be observed without changing the type of matter. Examples of physical properties include: texture, shape, size, color, odor, volume, mass, weight, and density.
• Hydrogen and oxygen react to make water• A match burns• A tree is cut down• Sodium reacts with water to make sodium
hydroxide• Rusting of iron • Boiling of water • Digestion of food • Boiling an egg.• Melting of ice
Circle the chemical changes
5. Circle the statements which state a physical property.
• The boiling point of water is 1000 C
• The density of ice is lower than liquid water
• Water reacts violently with sodium
• Hydrogen burns with a popping sound.
• The color of Copper compounds is blue.
The correct answer is D .The properties of shale do not change when it shatters.
1.
2.
B. Separating the water into its elements –freezing water, calculating the density of water, or dissolving sugar in water do not change the properties of water.
3.
D. In rusting, the metal combines with other atoms.
• Density Mass m Density = -------------- or D = ------- Volume v
• Adjust the density formula and solve the problems below:
• Mass=dxv
www.oil-check.com
Viscosity is the resistance of a fluid to flow.
Honey is more viscous than water.
Viscosity
What happens to the viscosity of a liquid when it is heated?
• Viscosity decreases when temperature is increased.
Hot honey flows faster than cold honey.
www.fas.harvard.edu/.../CokeCanBuoyancy002.jpg
Buoyancy is an upward force that keeps things afloat.
The density of water is
1.00g/ml.
www.dmturner.org http://www.csiro.au/files/images/paao.jpg
Water is more dense than oil so forms a layer below oil.
1. The density of silver is 10.49 g/cm3. If a sample of pure silver has a volume of 12.993 cm3, what is the mass?
Density = 10.49 g/cm3
Volume= 12.993 cm3,
Mass= DXV
10.49g/cm3 x 12.993cm3 =136.3 g
A pipette is filled to 12 mL of sulfuric acid at 250 C and has a density of 1.83 g/mL. According to this information, what is the mass of this sulfuric acid solution?
Sometimes a question will give you too much information.
Focus on what you are looking for – Mass
Mass = Density x volume
=1.83g/ml x 12ml
=21.96 g= 22.0g
Density of water is 1g/ml. If an object floats in water it’s density should be less than 1g/ml.
The only object that has adensity less than 1 is D.
D= M/V
= 60g/65cm3
=.92g/cm3
If a graphic is given, look at it carefully. In order to calculate mass, you need density and volume. Mass = density x volume
= 1.23g/ml x 19.4ml=23.9 g
4. A block of gold has a volume of 800 cubic centimeters and a density of 19.3g/cm3 and the block is divided into two equal blocks. What is the density of the two smaller blocks?
The density does not change when something is cut in half. The density of the two smaller blocks will also be 19.3 g/cm3
H -VISCOSITY
D. Decreases the viscosity
Three liquids were poured into a beaker and formed three layers.Which conclusion is best supported by the information above?
A The mass of Liquid 2 is greater than the mass of Liquid 3.
B The volume of liquid 1 is lass than the volume of Liquid 3.
C The density of Liquid 3 is greater than the density of Liquid 2.
D The buoyancy of Liquid 2 is greater that the buoyancy of Liquid 1.
C. The density of liquid 3 is greater than density of liquid 2.
Elements Compound and Mixtures
1. Circle the mixtures and underline the elements from the following list.
• Air• Sodium Chloride • Copper • Water • Bread • CaCl2 • Na
2. What is the difference between an element and a compound?
http://www.physicalgeography.net/fundamentals/images/compounds_molecules.jpg
An element is made up of only one kind of atom. A compound is made of two or more elements combined together in a fixed ratio.
A. An element cannot be physically separated into other substances.
F- Compounds
Define atomic number: __Atomic number is the number of protons in the nucleus of an atom. Lead has 82 protons in it's nucleus and so the atomic number of lead is 82.
Which subatomic particles are present in the nucleus of an atom?
Protons and neutrons are present in the nucleus of an atom.
Which of the sub atomic particles determines the identity of an element?
Proton
What does an atom lose when a positive ion is formed? _____________
An atom loses an electron to form a positive ion.
Bohr models
• Sodium
Atomic structure
Group : 1
Valence electrons : 1
Ion formed : +1
Chlorine
Atomic structure
Group : 17
Valence electrons : 7
Ion formed : -1
Neon
Atomic Structure
Group : 18
Valence electrons : 8
Does not lose or gain electrons
Sulfur
Atomic structure
Group : 16
Valence electrons : 6
Ion formed : -2
• Sodium will lose one electron to attain noble gas configuration.
Metals, Nonmetals and Metalloids on the Periodic Table
Chapter 1
Metals
• Located on the ______ side
• Form ________
• Conduct heat and electricity
• Shiny appearance
• ________
• ______
left
Ductile
cations
Malleable
Non-metals
• Located on the RIGHT side of the periodic table (except for ___________)
• Form _______
• poor conductors of heat and electricity
• Many are _____ at______________GASES
HYDROGEN
ANIONS
ROOM TEMPERATURE
Metalloids
• located __________ the metals and non-metals
• Have properties of both metals and non-metals
• ______ at room temperatureSOLIDS
IN BETWEEN
SOLIDS
Metal/Nonmetal
1. Which of the following elements is a metal?
• oxygen• calcium• Antimony• hydrogen
2. Which of the following is not a metal?
• Magnesium
• Mercury
• Silicon
• Aluminum
Periodic Table and Trends
• 1. Which element has properties that are chemically most similar to the element Se?
• Cu• Te• Br• Sc
Te is in the same group as Se and so would be chemically similar to it.
2. Define mass number-
Mass number is the total number of protons and neutrons in the nucleus of an atom.
3. Which groups of atoms are the most chemically similar?
• C, N, O• C, N, P• N, P, As• Ge, As, S
N, P and As belong to the same group and therefore are most chemically similar.
4. The elements in the second vertical column of the periodic table are called?
Alkaline earth metals
5. Which of the following elements are in the same group as Boron?
• Gallium
• Nitrogen
• Silicon
• Aluminum
6. Which of the following elements is most likely to donate an electron?
• Strontium
• Sodium
• Carbon
• Neon
7. The elements of which group in the periodic table are most resistant to forming compounds ______________
Noble gases have 8 valence electrons; their outer energy levels are complete and so they do not react with anything and are resistant to forming compounds.
Noble gases
8. According to the periodic table what is the name of the group of elements that most readily accept electrons?
Halogens – Group 17 have 7 valence electrons, they need only one more to complete their octet .This group therefore accepts electrons most readily
9. Name four other elements that will have the same properties as
Oxygen.
• S, Se , Te , Po
10. How many electrons should potassium gain or lose to attain a noble gas configuration?
Potassium has 1 valence electron. When it loses the one valence electron, it now has 8 in its outer energy level.
11. How many valence electrons are in an iodine atom?
seven
Elements in group 16 have six valence electrons. They need two more to complete an octet, so they gain two electrons when bonding.
The nucleus of Carbon atom contains 6 protons. This is the carbon atom.
Answer - B
Gaining or donating electrons depends on how many valence electrons an element has.
Be in group 2 has 2 valence electrons , so it will donate two electrons.
Cs has one valence electrons so it will donate one valence electron.
The correct answer is G
Noble gases have 8 valence electrons. They undergo the fewest chemical reactions since their octet is complete.
The correct answer is T.
Answer – H
The other element which will have the same properties as calcium should be in the same group as calcium – which is strontium.
Bonding
1. An example of ionic bonding is between _________.
• a metal and a metal
• a metal and a nonmetal
• a nonmetal and a nonmetal
2. What is Covalent Bonding?
When atoms bond using covalent bonding the atoms share electrons in their outer shell creating full shells for both.
3. Based on their position in the periodic table, what kind of bond is present in the following?
• a) Magnesium and Oxygen
• b) Potassium and chlorine
• c) Carbon and chlorine
• d) Sodium and Sulfur
• e) Sulfur and oxygen
ionic
ionic
covalent
ionic
covalent
4. Write the correct formula for the ionic compound containing B+3 and CO3
-2.
B+3 CO3-2.
Swap and Drop B2 (CO3)3
Use the swap and drop method.
Al+3 SO4-2
Al2(SO4)3
B
To have the same characteristics and properties, the elements should lie in the same group. The element in the same group as oxygen is SULFUR - D
Group 16 elements have 6 valence electrons ,they need two more to become stable – Magnesium is able to donate those two electrons as it is in group 2 and so an ionic bond is formed between one Magnesium atom and one Oxygen atom.
Answer - G
Balancing Equations and Law of Conservation of Mass
• State the law of conservation of mass:
Law of conservation of mass states that mass can neither be created nor destroyed.
The total mass of the reactants is equal to the total mass of the products.
Define Coefficient: When we write chemical equations for a chemical reaction, we use special numbers called coefficients to represent multiple molecules or formula units. For example;
6H2OThe 6 in front of water is the coefficient and it means 6 molecules of water.
Answer -B
Count all the atoms on the reactant and product side .
Answer - J
Answer -C
Law of conservation of mass
Structure and properties of water
• The shape of a water molecule is _______. This makes water an extremely good solvent. Water is a universal solvent as it is able __________ a number of substances. Water molecule is polar in nature because the oxygen has a negative charge and hydrogen has a positive charge .
• Water is unique because liquid water is _____ dense then ice. Ice is able to float on water. This helps fish to survive in extreme cold.
bent
dissolve
more
B. High Polarity
H. Expand when it freezes ,creating a floating and insulating layer of ice.
Structure of ice
Water molecules are polar.
F. The sodium ion has a positive charge and the oxygen atom carries a negative charge.
Rate of reaction and Solubility Curves
Factors that affect the rate of reaction:
• Temperature• Surface area- Crushing INCREASES
surface area.• Agitation
• An increase in temperature usually increases the solubility of solids in water but decreases the solubility of gases in liquids
An increase in pressure increases the solubility of gases in liquids but does not affect the solubility of solids in liquids
http://www.chem.ufl.edu/~itl/2045/change/C12F14.GIF
B. 48oC
Answer
F. 00C
Increased water temperature will decrease the solubility of the gases in it.
The correct answer is D.
Acids and Bases
Properties of acids
• Acids are sour to taste• Acids turn blue litmus red• Acids react with bases to form salt and
water • Acids are corrosive • Ph of an acid is less than 7• Strong acids are strong electrolytes
Properties of bases
• Bases are bitter • Bases turn red litmus blue. • Bases react with acids to form water and
salt • Most of the bases are cleaning products• pH of a base is more than 7 • Strong bases are strong electrolytes
Examples of acids
• HCl- Hydrochloric acid• Sulfuric acid – H2SO4
• Phosphoric acid –H3PO4
• Hydrobromic acid -HBr• Nitric Acid –HNO3
Examples of bases
• NaOH- Sodium Hydroxide • Ba (OH) 2- Barium Hydroxide • Ammonia – NH3
• Calcium Hydroxide – Ca (OH)2
• Acids have a high concentration of H+ ions
• Bases have a high concentration of OH- ions
• Water has an equal amount of H+ and OH- ions.
• Water has a pH of 7
Since the pH is increasing the added unknown must be a base. A base has higher OH- ions. Answer - D
An acid has a pH below 7 . Strong acids are strong electrolytes that has a high conductivity – Acids turn red litmus blue. Answer is D
An electrolyte is any substance containing free ions that behaves as an electrically conductive medium. Because they generally consist of ions in solution, electrolytes are also known as ionic solutions. Acids, bases and salts are good electrolytes.
3. Define electrolyte.
4. Why is NaCl a strong electrolyte?
NaCl Breaks apart into Na+ and Cl- ions in water. In an electric field the Na+ ions move toward the negative electrode, the Cl- ions move towards positive electrode, creating an electric current.
5. Why does distilled water not conduct electricity?
The salts in tap water fall apart into electrically charged particles (ions) in water. In an electrical field, these ions are dragged one way or the other, depending on their charge, producing an electric current .
From distilled water all ions have been removed, so it does not conduct electric current .
J. Concentrations of ions in solution increases by dissolving salt in water. Salt produces ions in solution that increases the conductivity of solution.
J. Bath water has dissolved minerals and so it shows electrolytic behavior.
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