1. Define Physical Change. Physical changes occur when objects undergo a change that does not change their chemical nature. 2. Define Chemical Change.
Physical changes occur when objects undergo a change that does not change their chemical nature.
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.
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.
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:
Viscosity is the resistance of a fluid to flow.
Honey is more viscous than water.
Hot honey flows faster than cold honey.
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,
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.
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 a density of 19.3g/cm3 and the block is divided into two equal blocks. What is the density of the two smaller blocks?
D. Decreases the viscosity a density of 19.3g/cm3 and the block is divided into two equal blocks. What is the density of the two smaller blocks?
Elements Compound and Mixtures liquid 2.
Circle the mixtures and underline the elements from the following list.
2. liquid 2.What is the difference between an element and a compound?
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.
F- Compounds substances.
Define atomic number: __ substances.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.
Protons and neutrons are present in the nucleus of an atom.
What does an atom lose when a positive ion is formed? _____________
An atom loses an electron to form a positive ion.
Group : 1
Valence electrons : 1
Ion formed : +1
Group : 17
Valence electrons : 7
Ion formed : -1
Group : 18
Valence electrons : 8
Does not lose or gain electrons
Group : 16
Valence electrons : 6
Ion formed : -2
Chapter 1 configuration.
Metals, Nonmetals and Metalloids on the Periodic Table
Located on the ______ side
Conduct heat and electricity
located __________ the metals and non-metals
Have properties of both metals and non-metals
______ at room temperature
1. Which of the following elements is a metal?
2. Which of the following is not a metal? configuration.
Periodic Table and Trends configuration.
1. Which element has properties that are chemically most similar to the element Se?
Te is in the same group as Se and so would be chemically similar to it.
2. Define mass number- configuration.
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? configuration.
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
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.
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
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? attain a noble gas configuration?
Elements in group 16 have six valence electrons. They need two more to complete an octet, so they gain two electrons when bonding.
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 fewest chemical reactions since their octet is complete.
The other element which will have the same properties as calcium should be in the same group as calcium – which is strontium.
Bonding fewest chemical reactions since their octet is complete.
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? fewest chemical reactions since their octet is complete.
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
4. Write the correct formula for the ionic compound containing B+3 and CO3-2.
Swap and Drop B2 (CO3)3
Use the swap and drop method. containing 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
Answer - G 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.
Balancing Equations and Law of Conservation of Mass elements should lie in the same group. The element in the same group as oxygen is SULFUR - D
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.
When we write chemical equations for a chemical reaction, we use special numbers called coefficients to represent multiple molecules or formula units. For example;
The 6 in front of water is the coefficient and it means 6 molecules of water.
Answer -B use special numbers called coefficients to
Count all the atoms on the reactant and product side . use special numbers called coefficients to
Answer - J
Answer -C use special numbers called coefficients to
Law of conservation of mass use special numbers called coefficients to
Structure and properties of water use special numbers called coefficients to
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.
B. High Polarity use special numbers called coefficients to
Structure of ice use special numbers called coefficients to
H. Expand when it freezes ,creating a floating and insulating layer of ice.
Water molecules are polar. use special numbers called coefficients to
F. The sodium ion has a positive charge and the oxygen atom carries a negative charge.
Rate of reaction and Solubility Curves atom carries a negative charge.
Factors that affect the rate of reaction:
Surface area- Crushing INCREASES surface area.
An increase in pressure increases the solubility of gases in liquids but does not affect the solubility of solids in liquids
B. 48 liquids but does not affect the solubility of solids in liquids oC
Answer liquids but does not affect the solubility of solids in liquids
Increased water temperature will decrease the solubility of the gases in it.
The correct answer is D.
Acids and Bases the gases in it.
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 the gases in it.
Examples of acids the gases in it.
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 the gases in it.
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 electrolytes that has a high conductivity – Acids turn red litmus blue. Answer is Delectrolyte 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.
NaCl Breaks apart into Na electrolytes that has a high conductivity – Acids turn red litmus blue. Answer is D+ 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.
4. Why is NaCl a strong electrolyte?
5. Why does distilled water not conduct electricity? electrolytes that has a high conductivity – Acids turn red litmus blue. Answer is D
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. dissolving salt in water. Salt produces ions in solution that increases the conductivity of solution. Bath water has dissolved minerals and so it shows electrolytic behavior.