Quiz Standard 1 Answer Key
Teacher Name: / Quiz Generated On: 04-28-20161)
Identify the number of neutrons in one atom of sulfur with an isotopic mass number of 34 amu.
A) / 16B) / 18
C) / 32
D) / 34
E) / None of the above
Explanation:
One atom of sulfur with an isotopic mass number of 34 has 18 neutrons. 34 (total) - 16 (protons) = 18 (neutrons).
2) Which is true of ionic compounds?
A) / They are good conductors as solids.B) / They are made by sharing electrons.
C) / They are made of metals and nonmetals.
D) / They are electrically neutral when dissolved in a solution.
E) / None of the above
Explanation:
They are made of metals and nonmetals is true of ionic compounds. They usually form between elements on opposite sides of the periodic table. Ionic compounds are only good conductors when molten or dissolved. When dissolved, they form ions, charged particles. Ionic compounds transfer electrons.
3) Which is true of all covalent compounds?
A) / They share electrons in bonds.B) / They are electrically charged.
C) / They are good conductors in water.
D) / They are usually made of a metal and a nonmetal.
E) / None of the above
Explanation:
All covalent compounds share electrons in bonds. They are made of two or more nonmetals which share electrons. They do not form ions, charged particles, so they are not good conductors in water.
4) A positively charged ion will bond with
A) / a negatively charged ion.B) / a neutral atom.
C) / another positively charged ion.
D) / nothing else.
E) / None of the above
Explanation:
A positively charged ion will bond with a negatively charged ion. Have you ever heard the phrase "opposites attract"?
5) The electrical charge on an atom as a whole is
A) / negative.B) / neutral.
C) / positive.
D) / dependent upon the atomic number.
E) / None of the above
Explanation:
The electrical charge on an atom as a whole is neutral. The number of positive protons and negative electrons is equal.
6) The atomic number of magnesium is 12. Its nucleus must contain
A) / 6 protons and 6 neutrons.B) / 6 neutrons and 6 electrons.
C) / 12 neutrons and no protons.
D) / 12 protons and no electrons.
E) / None of the above
Explanation:
The atomic number of magnesium is 12. Its nucleus must contain 12 protons and no electrons. The atomic number of an atom is determined by the number of protons. Electrons are not in the nucleus.
7) When K+ and I- combine, a(n) ______bond results.
A) / covalentB) / ionic
C) / metallic
D) / polyatomic
E) / None of the above
Explanation:
When 2 ions such as K+ and I- combine an ionic bond results.
8) In ______, electrons are gained by atoms and lost by others.
A) / ionic bondsB) / covalent bonds
C) / metallic bonds
D) / polyatomic bonds
E) / None of the above
Explanation:
Ionic bonds occur between metals and nonmetals. Metals have fewer valence electrons than nonmetals and will give their valence electrons to a nonmetal in order to become more stable.
9) ______are bonds in which valence electrons are shared.
A) / Ionic bondsB) / Atomic bonds
C) / Covalent bonds
D) / Hydrogen bonds
E) / None of the above
Explanation:
When nonmetals combine in covalent bonds they share valence electrons.
10)
What is the number of protons in an atom of sodium?
A) / 11B) / 11.9897
C) / 12
D) / 23
E) / None of the above
Explanation:
Sodium has 11 protons. The atomic number is the same as the number of protons for each element. From the periodic table, the atomic number is the whole number that is used to put the elements in order. For sodium, it is 11.
11) Electrons are transferred in the formation of ______bonds.
A) / ionicB) / covalent
C) / metallic
D) / all chemical
E) / None of the above
Explanation:
In ionic bonds, electrons are transferred to satisfy their outer energy level. Electrons are shared in covalent bonds.
12) A carbon-12 atom has 6 protons, 6 neutrons, and 6 electrons. How many protons does a carbon-14 atom have?
A) / 6B) / 8
C) / 12
D) / 14
E) / None of the above
Explanation:
The correct number of protons is 6. All isotopes of any element have the same number of protons.
13) Which statement is the BEST definition of an atom?
A) / Anything that has mass and occupies space.B) / The smallest particle that has the properties of an element.
C) / A substance that cannot be broken down chemically into simpler substances.
D) / The smallest unit of a substance that exhibits all of the properties characteristic of that substance.
E) / None of the above
Explanation:
The smallest particle that has the properties of an element, is the correct definition of an atom. A is the definition of matter; C is the definition of an element; and D is the definition of a molecule.
14)
This image is an example of a(n)
A) / atom.B) / compound.
C) / mixture.
D) / molecule.
E) / None of the above
Explanation:
The correct answer is atom. It is the smallest unit of an element, all of the others require more than one element.
15)
Order these elements from LEAST to GREATEST atomic mass.
A) / Li, He N, SB) / He, Li, N, S
C) / N, He, Li, S
D) / S, N, Li, He
E) / None of the above
Explanation:
He, Li, N, S orders these atoms from LEAST to GREATEST atomic mass. Atomic mass is the average atomic mass of the most abundant isotopes of an element. Simply add the number of protons and neutrons.
16) Describe the composition of the nucleus of an atom.
A) / It is composed of protons.B) / It is composed of protons and neutrons.
C) / It is composed of protons and electrons.
D) / It is composed of protons, neutrons, and electrons.
E) / None of the above
Explanation:
An atomic nucleus is composed of protons and neutrons. The electrons are located in the outer electron cloud.
17)
The compound formed has a(n) ______bond and is a(n) ______.
A) / ionic; crystalline solidB) / covalent; amorphous solid
C) / metallic; crystalline solid
D) / covalent; crystalline solid
E) / None of the above
Explanation:
The compound formed has ionic bonds and is a crystalline solid. A metal plus a nonmetal chemical combine to form an ionic compound, with ionic bonds. Nearly all ionic compounds are crystalline solids at room temperature.
18) Which is a sub-atomic particle?
A) / compoundB) / electron
C) / isotope
D) / neuron
E) / None of the above
Explanation:
Electrons are an example of a sub-atomic particle, which is found outside of the nucleus of an atom. Isotopes are forms of elements with different numbers of neutrons, neurons are brain cells, and a compound is two or more elements chemically combined.
19)
What is the result of the process that occurs in the image?
A) / two stable ions formed and able to exist independentlyB) / one unstable compound that will only exist for a short period
C) / two ions formed and attracted to one another to form a stable compound
D) / two unstable ions which will immediately look for a substance with which to react
E) / None of the above
Explanation:
Lithium fluoride is created when these two ions are formed and attracted to one another to form a stable compound,LiF. By moving one electron from lithium, its outer shell is now full (with two). Additionally, by adding this electron to fluorine, it gains a full, stable octet.
20) Which statement correctly explains how magnesium and chlorine combine to form magnesium chloride?
A) / A Cl atom donates two electrons to a Mg atomB) / An Mg atom donates two electrons to a Cl atom.
C) / A Cl atom donates one electron to each of the two Mg atoms.
D) / An Mg atom donates one electron to each of the two Cl atoms.
E) / None of the above
Explanation:
Cl has 7 electrons in its outermost orbit. It needs one electron to attain stability. So, a Mg atom donates one electron to each of the two Cl atoms to form MgCl2.
Quiz Standard 2 Answer Key
Teacher Name: / Quiz Generated On: 04-28-20161) Lenny accidentally drops his matchbox car into a graduated cylinder. If the car has a mass of 10 grams and the water level in the cylinder rises from 41 ml to 46 ml. Determine the density of the matchbox car. The formula for density is D =
mv
.
A) / 0.5 g/mlB) / 2 g/ml
C) / 15 g/ml
D) / 50 g/ml
E) / None of the above
Explanation:
The matchbox car has a density of 2 g/ml. Density = mass/volume = 10g/5mL=2 g/mL.
2) To find the density of an object you would use a graduated cylinder to find what characteristic of the object?
A) / lengthB) / mass
C) / volume
D) / weight
E) / None of the above
Explanation:
Graduated cylinders measure volume. The height of a column of water indicates how many milliliters an object occupies.
3) A balanced chemical reaction obeys the law of
A) / ideal gases.B) / definite proportions.
C) / conservation of matter.
D) / conservation of energy.
E) / None of the above
Explanation:
It obeys the law of conservation of matter because you are putting the same amount of matter on each side of the equation.
4) Which is a unit of density?
A) / cm3/gB) / g/cm
C) / g/cm3
D) / ml/g
E) / None of the above
Explanation:
g/cm3 is a measure of density. It represents mass over volume, which is density.
5) What is the chemical formula for the binary compound nitrogen dioxide?
A) / (NO)2B) / 1N2Ox
C) / NO2
D) / nitro1oxide2
E) / None of the above
Explanation:
The lack of a prefix on nitrogen tells you that there must be one nitrogen and the prefix di on oxide tells you that there must be two oxygen atoms. The number of atoms is denoted by its subscript. Therefore, the formula must be NO2.
6) When magnesium (Mg2+) and fluorine (F1-) combine in an ionic bond, the resulting formula will be
A) / Mg2F.B) / Mg2F2.
C) / MgF.
D) / MgF2.
E) / None of the above
Explanation:
MgF2 is the correct formula because magnesium has an oxidation number of 2+ and fluorine has and oxidation number of 1-. The oxidation number tells you how many valence electrons the element is going to gain, loose, or share.
7) Lithium is a metal with an oxidation number of 1+ and oxygen is a nonmetal with an oxidation number of 2-. Which chemical formula represents the compound formed by these two elements?
A) / Li2OB) / Li3O
C) / LiO
D) / LiO2
E) / None of the above
Explanation:
Li2O is the correct answer because lithium has one valence electron and oxygen has six. Therefore, oxygen bonds with 2 lithium atoms to complete the outer shell of 8.
8) Which compound is an example of a binary ionic compound?
A) / H2OB) / H2SO4
C) / MgF2
D) / SF6
E) / None of the above
Explanation:
MgF2 is the only binary ionic compound because binary means two and an ionic compound is formed between a metal and a nonmetal.
9)
NOName this compound according to IUPAC nomenclature rules.
A) / nitrogen oxideB) / nitrogen oxygen
C) / nitrogen monoxide
D) / mononitrogen monoxide
E) / None of the above
Explanation:
Nitrogen monoxide is the correct answer. The first element doesn't need a prefix for one; but the second element does.
10) Which nonmetal would an ion of Ca2+ MOST LIKELY ionically bond with in a 1:1 ratio?
A) / one atom of neonB) / one atom of carbon
C) / one atom of oxygen
D) / one atom of fluorine
E) / None of the above
Explanation:
The correct choice is one atom of oxygen. Ionic bonds form between oppositely charged ions, therefore, calcium has a 2+ charge and is attracted to oxygen with 2- charge. The others have too much or too little of a charge.
11)
KClO3 ---> KCl + O2Balance the decomposition chemical reaction.
A) / KClO3 ---> KCl + O2B) / 2KClO3 ---> KCl + 3O2
C) / 2KClO3 ---> 2KCl + 3O2
D) / 2KClO3 ---> 2KCl + 6O2
E) / None of the above
Explanation:
The correctly balanced decomposition reaction is 2KClO3 ---> 2KCl + 3O2. The others are not balanced because the number of atoms do not balance on both sides of the equation.
12)
CuCl2 + Al ---> AlCl3 + CuBalance the single replacement chemical reaction.
A) / CuCl2 + Al ---> AlCl3 + CuB) / 3CuCl2 + 2Al ---> 2AlCl3 + 3Cu
C) / 2CuCl2 + 3Al ---> 3AlCl3 + 2Cu
D) / 3CuCl2 + 3Al ---> 3AlCl3 + 3Cu
E) / None of the above
Explanation:
The correctly balanced single replacement reaction is 3CuCl2 + 2Al ---> 2AlCl3 + 3Cu. The others are not balanced, the number of atoms on both sides of the equation do not balance.
13)
Pb(NO3)2 + K2CrO4 ---> PbCrO4 + 2KNO3Classify the chemical reaction.
A) / synthesis reactionB) / decomposition reaction
C) / single replacement reaction
D) / double replacement reaction
E) / None of the above
Explanation:
The correct classification is double recplacement reaction. The lead and the potassium replace each other making this a double replacement reaction.
14)
NaCl + H2SO4 ---> Na2SO4 + HClBalance the double replacement chemical reaction.
A) / NaCl + H2SO4 ---> Na2SO4 + HClB) / 2NaCl + H2SO4 ---> Na2SO4 + 2HCl
C) / 3NaCl + 2H2SO4 ---> 2Na2SO4 + 3HCl
D) / 2NaCl + 2H2SO4 ---> 2Na2SO4 + 2HCl
E) / None of the above
Explanation:
The correctly balanced double replacement reaction is 2NaCl + H2SO4 ---> Na2SO4 + 2HCl. This is the only equation in which the number of atoms is equal on both sides the equation.
15)
NI3 is an extremely sensitive contact explosive.Use IUPAC rules to name this compound.
A) / nitrogen iodideB) / nitrogen triiodide
C) / mononitrogen iodide
D) / mononitrogentriiodide
E) / None of the above
Explanation:
NI3 would be called nitrogen triiodide. The nitrogen, being the first element with only one atom, does not require a prefix. Iodine has the ending changed to "ide" and there are three, so a prefix of "tri" is added.
16)
reactant → productIf there are 2 grams of product produced by the chemical reaction, how many grams of reactant were consumed?
A) / 0 gramsB) / 1 gram
C) / 2 grams
D) / 4 grams
E) / None of the above
Explanation:
2 grams of reactants would be consumed by the chemical reaction. The mass of the reactants equals the mass of the products. This is the Law of Conservation of Matter. However much is reacted must be produced.
17)
A + B + C → D + EDescribe the mass of the reactants and products given the balanced chemical reaction.
A) / The mass of the products is 2/3 that of the reactants.B) / The mass of the reactants equals the mass of the products.
C) / The mass of the reactants is less than the mass of the products.
D) / The mass of the reactants is greater than the mass of the products.
E) / None of the above
Explanation:
The mass of the reactants equals the mass of the products. This is the Law of Conservation of Matter. Do not be fooled by the larger numbers of reactants.
18)
4Fe + 3O2 → 2Fe2O3Iron combines with oxygen to form rust. Given the chemical reaction, how many grams of 4Fe + 3O2 would produce 10 kg of rust?
A) / 7 kgB) / 10 kg
C) / 30 kg
D) / 70 kg
E) / None of the above
Explanation:
10 kgof 4FE + 3O2 would be required to produce 10 kg of rust. This is the Law of Conservation of Matter.
19)
K2OUse IUPAC nomenclature rules to properly identify this compound.
A) / potassium oxideB) / dipotassium oxide
C) / potassium (I) oxide
D) / dipotassium monoxide
E) / None of the above
Explanation:
The correct name is potassium oxide. It is a binary ionic compound, so no prefixes are used. Since potassium is a representative metal with only one possible charge, no roman numerals are used.
20) Hydrogen peroxide is a chemical used to clean bacteria out of cuts. It does this through creating germ-eating oxygen in this decomposition reaction. What set of coefficients, respectively, balance this equation?
H2O2 → H2O + O2
A) / 1 → 1,2B) / 2 → 2,1
C) / 2 → 2,2
D) / 4 → 4,1
E) / None of the above
Explanation:
2 → 2,1 Start by balancing the O, by putting a 2 in front of H2O (this gives an even number of O). This creates a total of 4 O on the product side and 4 H. To balance the H, put a coefficient of 2 on the reactant side.
21)
The correct chemical formula for magnesium sulfide is
A) / Mg2SB) / Mg3S4
C) / MgS
D) / MgS2
E) / None of the above
Explanation:
The correct chemical formula for magnesium sulfide is MgS. This is an ionic compound. The Mg ion has a charge of 2+, the sulfide a charge of 2-, so they bond in a 1:1 ratio.
22)
Fe(s) + CuSO4(aq) → FeSO4(aq) + Cu(s)This chemical equation represents a ______reaction.
A) / synthesisB) / decomposition
C) / neutralization
D) / single replacement
E) / None of the above
Explanation:
The type of reaction represented by the balanced chemical equation is single replacement reaction. In this case, one metal, iron (Fe), replaces another metal, copper (Cu) in copper sulfate (CuSO4).
23) Carbon and flourine combine covalently to form a binary compound. What is the formula of the compound with the name carbon tetrafluoride?
A) / C4FB) / C4F4
C) / CF
D) / CF4
E) / None of the above
Explanation:
When writing the formula for covalent compounds, remember that the name tells you the number of atoms for each. Carbon, having no prefix, is one and flourine has a prefix of four. So, the correct answer is CF4.
24)
Data Analysis
Elements / DensityAluminum / 2.698 g/mL
Calcium / 1.54 g/mL
Iron / 7.8738 g/mL
Silicon / 2.3296 g/mL
Sanjay is learning about the elements that make up Earth’s crust. Ms. Richards, his Earth science teacher, gives him an element and asks him to determine which element from Earth’s crust it is. She also provides Sanjay with this table. Sanjay weighs the element and finds that it has a mass of 17.98 g. By placing the element in water, he determines the volume of the substance to be 2.2835 mL.
Based on the table from Ms. Richards, what element from Earth’s crust did Ms. Richards gave to Sanjay?
B) / calcium
C) / aluminum
D) / silicon
E) / None of the above
Explanation:
By using the table from Ms. Richards, Sanjay can determine what element from Earth’s crust he has by finding its density. To find density, Sanjay must use the formula density =
volume
. The equation he will use is density =
17.98 g2.2835 mL
. Therefore, the density of this element is 7.8738
gmL
. Based on the table, the element with a density of 7.8738
gmL
isiron, which is the element from Earth’s crust Ms. Richards gave to Sanjay.
25) The law of conservation of matter states that during a chemical reaction, the amount of matter
A) / increases.B) / decreases.
C) / disappears.
D) / stays the same.
E) / None of the above
Explanation:
The law of conservation of matter says that matter always stays the same during chemical reactions. Physical or chemical changes result in matter being converted to other forms.
26)
8Fe + S8 --> 8FeSWhat type of chemical reaction is happening here?
A) / synthesisB) / decomposition
C) / single replacement
D) / double replacement
E) / None of the above
Explanation:
This is a synthesis reaction. All synthesis reactions end up with one product being formed from two or more reactants.
27)
Common Metals
Name / Melting Point / Density (g/cm3)Zinc / 419.53 oC / 7.134
Nickel / 1455oC / 8.912
Copper / 1084.62oC / 8.96
Silver / 961.78oC / 10.501
Gold / 1064.18oC / 19.282
Determine the identity of a cube of metal that measures 1.5 cm on each side and has a mass of 35.45g.
A) / GoldB) / Nickel
C) / Silver
D) / Zinc
E) / None of the above
Explanation:
Based on the density calculation, the cube must be made of silver. To determine the density, divide the mass by the volume. The volume = l x w x h. Since this is a cube, the volume = (1.5cm)3 = 3.375 cm3. D =
v
=
35.45g3.375cm3
= 10.50
gmL
, so this must be silver according to the chart.
28)
How should you change this image to represent an ionic bond between sodium and fluorine?
A) / Move 7 electrons from fluorine to sodium.B) / Move one electron from fluorine to sodium.
C) / Move one electron from sodium to fluorine.
D) / Nothing. The image already represents an ionic bond.
E) / None of the above
Explanation:
The correct answer is Move one electron from sodium to fluorine. Non metals take electrons from metals to form ionic bonds.
29) What is the chemical formula for potassium oxide?
A) / K2OB) / KO2
C) / PO
D) / PO2
E) / None of the above
Explanation:
The correct formula for potassium oxide is K2O. First, be sure you have the correct symbols for each element. Then check the oxidation/valence number: potassium (K) is +1 and oxygen (O) is -2. Using the criss-cross method to be sure that the sum of the oxidation numbers equals zero, we have K2O.
30) What is the chemical formula for aluminum fluoride?
A) / Al3FB) / AlF
C) / AlF3
D) / AlFl3
E) / None of the above
Explanation:
The correct formula for aluminum fluoride is AlF3. First, be sure you have the correct symbols for each element. The symbol for fluorine is F. Then check the oxidation/valence number: aluminum (Al) is +3 and fluorine (F) is -1. Using the criss-cross method to be sure that the sum of the oxidation numbers equals zero, we have AlF3.