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WorksheetsChemistry Midterm review 2020-2021
Total questions: 31
Worksheet time: 36mins
The diagram below represents the nucleus of an atom. What are the atomic number and mass number of this atom?
The atomic number is 9 and the mass number is 19.
The atomic number is 9 and the mass number is 20.
The atomic number is 11 and the mass number is 19.
The atomic number is 11 and the mass number is 20.
Which properties are characteristic of Group 2 elements at STP?
good electrical conductivity and electronegativities less than 1.7
good electrical conductivity and electronegativities greater than 1.7
poor electrical conductivity and electronegativities less than 1.7
poor electrical conductivity and electronegativities greater than 1.7
Compared to an atom of C-12, an atom of C-14 has a greater
number of electrons
number of protons
atomic number
mass number
Based on Table S, which group on the Periodic Table has the element with the highest electronegativity?
Group 1
Group 2
Group 17
Group 18
Which electron transition in an excited atom results in a release of energy?
first shell to the third shell
second shell to the fourth shell
third shell to the fourth shell
fourth shell to the second shell
Given the balanced equation representing a reaction
H2 + energy -->H + H What occurs as bonds are broken in one mole of H2 molecules during this reaction?
Energy is absorbed and one mole of unbonded hydrogen atoms is produced.
Energy is absorbed and two moles of unbonded hydrogen atoms are produced.
Energy is released and one mole of unbonded hydrogen atoms is produced.
Energy is released and two moles of unbonded hydrogen atoms are produced.
The chemical formula for nickel (II) bromide is
NiBr2
N2Br
NBr2
Which statement classifies the two compounds?
Both compounds are ionic.
Both compounds are molecular
Compound 1 is ionic, and compound 2 is molecular.
Compound 1 is molecular, and compound 2 is ionic
The gram-formula mass of is (NH4)2CO3 is
46.0 g
64.0 g
78.0 g
96.0 g
Explain, in terms of the strength of intermolecular forces, why the boiling point of water is higher than other liquids?
Explain, in terms of charge distribution, why a molecule of butanamide is polar.
A sample of calcium carbonate, CaCO3, has a mass of 42.2 grams. Calcium carbonate has a gram-formula mass of 100. g/mol. Determine the percent composition by mass of oxygen in the CaCO3.
State the number of electrons shared between the carbon atoms in a molecule of vinyl chloride.
Explain, in terms of substances in the reaction, why the equation represents a chemical change.
An ion that consists of 7 protons, 6 neutrons, and 10 electrons has a net charge of
4–
3-
3+
4+
Which Lewis electron-dot diagram represents calcium oxide?
A
B
C
D
When an atom becomes a positive ion, the radius of the atom
decreases
increases
remains the same
Which factor distinguishes a metallic bond from an ionic bond or a covalent bond?
the mobility of electrons
the mobility of protons
the equal sharing of electrons
the unequal sharing of electrons
Which statement describes the charge and location of an electron in an atom?
An electron has a positive charge and is located outside the nucleus.
An electron has a positive charge and is located in the nucleus.
An electron has a negative charge and is located outside the nucleus.
An electron has a negative charge and is located in the nucleus.
A mixture of crystals of salt and sugar is added to water and stirred until all solids have dissolved. Which statement best describes the resulting mixture?
The mixture is homogeneous and can be separated by filtration.
The mixture is homogeneous and cannot be separated by filtration.
The mixture is heterogeneous and can be separated by filtration.
The mixture is heterogeneous and cannot be separated by filtration.
Recovering the salt from a mixture of salt and water could best be accomplished by
evaporation
Filtration
paper chromatography
density determination
The chemical properties of calcium are most similar to the chemical properties of
Ar
K
Mg
Sc
Which sequence correctly places the elements in order of increasing ionization energy?
H -->Li --> Na --> K
I --> Br --> Cl --> F
O --> S--> Se --> Te
Base your answer to the following question on your knowledge of chemical bonding and on the Lewis electron-dot diagrams of H2S CO2 and F2 below.
Explain, in terms of electronegativity, why a C–O bond in CO2 is more polar than the F–F bond in F2
How many electrons would a Cl- ion have?
How many electrons would a Silicon atom have?
Which type of bond is formed by the transfer of electrons from one atom to another?
a covalent bond
a coordinate covalent bond
a hydrogen bond
an ionic bond
Which process represents a chemical change?
melting of ice
corrosion of copper
evaporation of water
crystallization of sugar
Which measurement has the greatest number of significant figures?
6.060 mg
60.6 mg
606 mg
60600 mg
What is the chemical formula for lead(IV) oxide?
PbO2
PbO4
Pb2O
Pb4O
What is the chemical formula for sodium oxalate?
NaO
Na2O
Na2C2O4
NaC2O4
