Chem exam 1 practice

Use the Periodic Table below to answer the question that follows. How many electrons does potassium need to lose to attain a noble gas configuration? Select the correct answer below: 5 1 3 8

1

How many neutrons are present in a 2512Mg atom? Select the correct answer below: 13 12 15 17

13

Use the Periodic Table below to answer the question that follows. Which group on the periodic table contains the chalcogens? Select the correct answer below: 1 2 16 17

16

Use the Periodic Table below to answer the question that follows. Caffeine is a stimulant present in coffee and tea. Its chemical formula is C8H10N4O2. What is the molecular mass of caffeine? Select the correct answer below: 194.194amu 67.037amu 43.030amu 316.551amu

194.194amu

Use the Periodic Table below to answer the question that follows. What is the ground state electron configuration of F? Select the correct answer below: 1s2 2s2 2p6 1s2 2s2 2p4 1s2 2s2 2p5 1s2 2s2 2p3

1s22s22p5

The oxygen atom in water has ______ lone pairs and _____ bonds. Select the correct answer below: 2, 2 2, 4 4, 4 4, 2

2, 2

The carbonate ion (CO3-2) has how many resonance forms? Select the correct answer below: 2 3 4 the carbonate ion doesn't have any resonance structures

3

How many d orbitals are there per energy level? Exclude energy levels n=1 and n=2 as these have no d orbitals. Report your answer as an integer (whole number) without any decimal places. Do not include units in your response.

5

Use the Periodic Table below to answer the question that follows. What is the atomic mass of iron? Select the correct answer below: 26 amu 126.913 amu 55.845 amu 192.215 amu

55.845 amu

Use the periodic table below to answer the question that follows. Magnesium hydroxide is used as an antacid as milk of magnesia. Its chemical formula is Mg(OH)2. What is the formula mass of magnesium hydroxide? Select the correct answer below: 25.319amu 88.947amu 41.333amu 58.319amu

58.319

Use the Periodic Table below to answer the question that follows. How many valence electrons does a fluorine atom ( F) have? Select the correct answer below: 1 2 5 7

7

Use the Periodic Table below to answer the question that follows. How many neutrons are present in an isotope of nitrogen that has a mass number of 15? Select the correct answer below: 15 22 8 7

8

What are the bond angles in the trigonal bipyramidal electron-pair geometry? Select the correct answer below: 109.5∘ only 109.5∘ and 120∘ 90∘ and 120∘ 120∘ only

90∘ and 120

Identify the Lewis structure of an oxygen atom. Select the correct answer below: :⋅⋅O⋅ ⋅⋅O⋅⋅ :⋅⋅O⋅⋅ none of the above

:⋅⋅O⋅⋅ C

In a molecule of water, H2O, which statement is most correct? Select the correct answer below: A molecule of water is made up of individual water atoms. A molecule of water is made up of two hydrogen atoms and one oxygen atom. A molecule of water is made up of one hydrogen molecule and one oxygen molecule. A molecule of water is made up of one hydrogen molecule and one oxygen atom.

A molecule of water is made up of two hydrogen atoms and one oxygen atom.

Which is NOT a postulate of Dalton's atomic theory? Select the correct answer below: Atoms are created and destroyed in a chemical reaction. Elements are made of one type of atom. Atoms of one element are different than atoms of another element. Compounds are atoms of two or more elements combined in a specific whole number ratio.

Atoms are created and destroyed in a chemical reaction.

Use the Periodic Table below to answer the question that follows. What is the chemical symbol for gold? Select the correct answer below: Au Ag Go Gd

Au

Use the Periodic Table below to answer the question that follows. Which is a hydrogen-like species? Select the correct answer below: He Li+ Be2+ B4+

B4+

What did classical physics predict about the structure of the atom? Select the correct answer below: Based on electrostatic attraction, the electrons are repelled by the protons in the nucleus. Based on electrostatic attraction, the electrons would spiral into the nucleus. Based on electrostatic attraction, the electrons were attracted to other electrons. Based on electrostatic attraction, atoms are inherently stable.

Based on electrostatic attraction, the electrons would spiral into the nucleus.

How are the physical sciences primarily divided? By the study of living vs. nonliving things By the size of the objects studied The study of moving vs. stationary entities None of the above

By the size of the object studied

The molecular formula of benzene is C6H6. What is the empirical formula of benzene? Select the correct answer below: C6H6 CH6 C6H CH

CH

Use the Periodic Table below to answer the question that follows. Which is NOT a molecular compound? Select the correct answer below: CS2 CaS SO2 SF6

CaS

Use the Periodic Table below to answer the question that follows. What is the name of the compound with the formula Cr(NO3)3? Select the correct answer below: Chromium (III) nitrate Chromium (II) nitrate Chromium trinitrate Chromium (I) nitrate

Chromium (III) nitrate

Which subatomic particle contributes a negligible mass (much less than 1 amu) to the mass of an atom? Select the correct answer below: Proton Neutron Electron Nucleon

Electrons

Use the Periodic Table below to answer the question that follows. Which bond is most polar? Select the correct answer below: F−F F−Cl F−Br F−I

F−I

Use the periodic table below to answer the question that follows. Which of the following elements has the smallest value of IE1? Select the correct answer below: F Br I Cl

I

Which is NOT a chemical change? Select the correct answer below: Fireworks explode Bananas ripen Nails rust Ice cubes melt

Ice cube melt

Which scientist determined that white light was made up of the individual colors of the rainbow combined together? Select the correct answer below: Isaac Newton Christiaan Huygens Thomas Young James Clerk Maxwell

Isaac Newton

A beaker contains solid sand and liquid water. Which statement describes the beaker's contents? Select the correct answer below: It is a pure substance, and the sand and water can only be separated chemically. It is a homogeneous mixture, and the sand and water can be physically separated by filtration. It is a heterogeneous mixture, and the sand and water can be separated by filtration. It is an element, and the sand and water cannot be separated even chemically.

It is a heterogeneous mixture, and the sand and water can be separated by filtration.

Use the Periodic Table below to answer the question that follows. A molecule has 9 valence electrons. What is true about its Lewis structure? Select the correct answer below: It will follow the octet rule. It will be an exception to the octet rule because it is an odd electron molecule. It will be an exception to the octet rule because it has an electron deficient central atom. It will be an exception to the octet rule because it is hypervalent.

It will be an exception to the octet rule because it is an odd electron molecule.

Use the periodic table below to answer the question that follows. Place the following in order of decreasing (i.e., largest to smallest) covalent radius.K,Si,Cl Select the correct answer below: K>Si>Cl Cl>Si>K Si>Cl>K K>Cl>Si

K>Si>Cl

Each box on the periodic table represents an element. What information is NOT contained in this box? Select the correct answer below: language of origin atomic symbol atomic number average atomic mass

Language of origin

Use the periodic table to answer question. What is the chemical formula for the ionic compound magnesium sulfide? Select the correct answer below: MS MgS Mg2S MgS2

MgS

Which is a polar molecule (has a molecular dipole moment)? Select the correct answer below: CF4 NF3 BF3 PF5

NF3

Use the periodic table below to answer the question that follows. What is the chemical formula of the ionic compound sodium sulfate? Select the correct answer below: Na(SO4)2 Na2(SO4)2 Na2SO4 NaSO4

Na2SO4

Use the Periodic Table below to answer the question that follows. Write the electron configuration for O2− ion. Select the correct answer below: O2−:1s2 2s2 2p6 3s2 O2−:1s2 2s2 2p4 O2−:1s2 2s2 2p6 O2−:1s2 2s2 2p4 3s2

O2−:1s22s22p6

Which describes J.J. Thomson's model of the atom? Select the correct answer below: Protons are localized in the nucleus of the atom. Electrons circulate around the nucleus in an atom. Protons and electrons are uniformly distributed throughout the atom. Protons and electrons are both found in the nucleus, with mostly empty space around.

Protons and electrons are uniformly distributed throughout the atom

Which subatomic particles are found within the nucleus? Select the correct answer below: Protons and electrons Protons only Protons and neutrons Neutrons and electrons

Protons and neutrons

Which is a polyatomic ion? Select the correct answer below: S2− Al3+ SO2−4 Na+

SO2-4

Use the periodic table below to answer the question that follows. Which of the following is an element? Select the correct answer below: Water Ammonia Sodium Carbon dioxide

Sodium

Which describes a solid? Select the correct answer below: Solids have a fixed shape and volume. Solids take the shape of their containers. Solids form a horizontal surface. Solids expand to fill their containers.

Solids have a fixed shape and volume.

Use the periodic table below to answer the question that follows. Which of the following ions has the largest radius? Select the correct answer below: O2− S2− Se2− Te2−

Te2−

What is weight? Select the correct answer below: The amount of matter present in an object The force exerted by gravity on an object The volume an object occupies The amount of time it takes an object to fall to earth

The force exerted by gravity on an object

What does the angular momentum quantum number, l, describe? Select the correct answer below: The energy level of the orbital. The shape of the orbital. The orientation in space of the orbital. The spin of the electron.

The shape of the orbital.

Molecules A and B are structural isomers of one another. What is true about molecules A and B? Select the correct answer below: They have different molecular formulas. They have different empirical formulas. They have the same structural formulas. They have different structural formulas.

They have different structural formulas

Predict the molecular structure of NO−3, whose Lewis structure is shown below. Tetrahedral Square pyramidal Trigonal planar Bent

Trigonal planar

Which of the following is a physical change? Select the correct answer below: Gasoline burns. Water freezes. Bread toasts. Metal rusts.

Water freeze

When are electron-pair geometries the same as molecular structures? Select the correct answer below: When the central atom is in the second period. When there is a lone pair on the central atom. When there are two or more lone pairs on the central atom. When there are no lone pairs on the central atom.

When there are no lone pairs on the central atom.

What does the law of multiple proportions state? Select the correct answer below: 1) All samples of a pure compound contain the same elements in the same proportion by mass. 2) When two elements react to form more than one compound, a fixed mass of one element will react with masses of the other element in a ratio of small, whole numbers. 3) For every action there is an equal and opposite reaction. 4) The total energy of the universe is constant

When two elements react to form more than one compound, a fixed mass of one element will react with masses of the other element in a ratio of small, whole numbers.

H2CO3(aq)+OH−(aq)→HCO−(aq)+H2O(l) Which type of process regarding a buffer system is represented in the above equation? Select the correct answer below: bicarbonate neutralizing an acid carbonic acid neutralizing a base both A and B none of the above

carbonic acid neutralizing a base

How many electrons are shared between the carbon atoms in ethylene? Select the correct answer below: One Two Four Eight

four