AP Chemistry Semester 1 2021

All alkaline earths have the following number of valence electrons...

2

Which molecules or ion violates the octet rule?

I3

Which formula would have the shape above?

NH3

Which of the following statements best describes the Heisenberg uncertainty principle?

It is impossible to accurately know both the exact location and momentum of a particle

Which diagram correctly depicts the trend in electronegativity?

diagram B

Atomic size is determined by measuring the

distance between nuclei of adjacent atoms

. . . . . . O == O -- O : . . . . In the resonance form of ozone shown, the formal charge on the central oxygen atom is _______

+1

A prospector finds 39.39 g of pure gold (atomic mass 196.9665 amu). She has

1.024 x 10^23 atoms of Au

The complete photoelectron spectrum of an element is given above. Which of the following electron configurations is consistent with the spectrum? *INSERT FREAKING PICTURE*

1s^22s^22p^63s^23p^3

40 Ca 2+ 20

20 protons, 20 neutrons, and 18 electrons

Expanded octet is possible with

3rd row and heavier elements using empty d orbitals

When the equation Fe3O4 + Al -> Al2O3 + Fe is correctly balanced, what is the coefficient of Fe?

9

The complete photoelectron spectrum for an element is shown above. Which of the following observations would provide evidence that the spectrum is consistent with the atomic model of the element? *INSERT FREAKING PICTURE*

A neutral atom of the element contains exactly two electrons

The photoelectron spectra above show the energy required to remove a 1s electron from a nitrogen atom and from an oxygen atom. Which of the following statements best accounts for the peak in the upper spectrum being to the right of the peak in the lower spectrum? *INSERT FREAKING PICTURES*

Nitrogen atoms have a smaller nuclear charge than oxygen atoms

Copper atoms and zinc atoms have the same atomic radius, 135 picometers. Based on this information, which of the following diagrams best represents an alloy containing only copper and zinc atoms?

B (the picture included in this question)

Without using and supplemental materials, predict which bond in each of the following groups will be the most polar

Ge-F

In writing a chemical equation that produces hydrogen gas, the correct representation of hydrogen gas is

H2

Choose the molecule wit the strongest bond.

HF

Choose the molecule with the strongest bond

HF

Which of the following pairs is isoelectronic?

Na+ and Ne

Which of the following atoms has the largest ionization energy?

Ne

Which of these statements is a consequence (follows from) the Law of Multiple Proportions?

The mass of oxygen that is combined with a fixed mass of nitrogen in each of the binary nitrogen oxides can be expressed as a ratio of small whole numbers

The electron pair in a C-F bond could be considered

closer to F because fluorine has a higher electronegativity than carbon

Predict the type of bond one would expect to form between the following pairs of elements N and P

covalent

As the size of the ions ________ and charges _________, lattice energy increases

decrease, increase

In a row in the periodic table, as the atomic number increases, the atomic radius generally

decreases

As the number of covalent bonds between two atoms increases, the distance between the atoms ______ and the strength of the bond between them _____

decreases, increases

To indicate resonance, a ____ is placed between a molecule's resonance structures

double-headed arrow

When an electron is acquired by a neutral atom, the energy change is called

electron affinity

A particle-level diagram of a metallic element is shown below. Typically, metals are both malleable and ductile. The best explanation for these properties is that the electrons involved in bonding among metal atoms are + + + + + + + + + - - - - - - - - - + + + + + + + + + - - - - - - - - - + + + + + + + + + - - - - - - - - + + + + + + + + +

equally shared and form nondirectional bonds

Atoms having equal or nearly equal or nearly equal electronegativities are expected to form

nonpolar covalent bond

Atoms having equal or nearly equal electronegativities are expected to form

nonpolar covalent bonds

Ionization energy is the energy required to remove __________ from an atom of an element

one electron

Coulombic Attraction is the attraction between _______ charged particles

oppositely

Nitrogen has five valence electrons. Consider the following electron arrangements. Which represents the ground state for N? INSERT PICTURE (image in similar question)

option a

Nitrogen has five valence electrons. Consider the following electron arrangements. Which represents the ground state for N-?

option e

Multiple covalent bonds may occur in atoms that contain carbon, nitrogen, or _______

oxygen

Which of the following best describes an orbital?

the space in an atom where an electron is most likely to be found

According to VSPER theory, the electrostatic repulsion between electron pairs surrounding an atom causes

these pairs to be separated as far as possible

Atoms naturally move

toward low potential energy

An element with the electron configuration [Xe]6s^14f^145d^1 would belong to which class on the periodic table?

transition elements

Which metals form cations with varying positive charges?

transition metals

Which of these bonds takes the most energy to break?

triple

Which lists the bonds of x, y, and z in decreasing order of length

x>y=z

Pair of electrons localized on an atom are called

lone pairs

Metals typically have _______ electronegativity values.

low

The correct name for FeO is

Iron (II) oxide

Which of the following arrangements is in order of increasing order?

Ga^3+ > Ca^2+ > K^+ > Cl^- > S^2-

Across a period in the periodic table, atomic radii

gradually decreases

---- ---- ---- ---- ---- ---- | :O: | | :O: | | :O: | | || | <---> | | | <----> | | | | / \ | | /\ | | / \\ | | :O: :O: | | :O: :O: | | :O: :O: | ---- ---- ---- ---- ---- ---- This is an example of _________

All of the above (Lewis structures, ions, resonance, delocalized ions)

What noble gas has the same electron configuration as rubidium phosphide? (select all that apply)

Ar, Kr

a 0,4987-g sample of a compound known to contain only carbon, hydrogen, and oxygen was burned in oxygen to yield 0.9267 g of CO2 and 0.1897 g of H2O. What is the empirical formula of the compound?

C3H3O2

o | | / | \ o o o Which formula would have the shape above?

CF4

Which of the following groups contains no ionic compounds?

CH2O, H2S, NH3

O-------O Which formula would have the above shape?

CO2

The photoelectron spectra of 1 s electrons of two isoelectronic species, Ca2+ and Ar, are shown above. Which of the following correctly identifies the species associated with peak X and provides a valid justification? * INSERT FREAKING PICTURE*

Ca2+, because its nucleus has two more proton than the nucleus of Ar has

The correct name for Ca2+ is

Calcium ion

Which compound in each of the following pairs of ionic substances has the most exothermic lattice energy?

CsF

What is the correct Lewis structure for hydrogen chloride, HCl? A. Cl---H: B. :H---Cl: C. :H---Cl: (6 unmatched electrons on Cl, i aint adding the other 4) D. H---Cl: (6 unmatched electrons on Cl, i aint adding the other 4)

D

Which of the following Lewis diagrams best represents the bonding in the N2O molecules, considering formal charges? A) . . . . : N==N==O: . . . . B) :N=_=_N--O: . . . . . . . . C) :N--N==O: . . . . D) :N--O==N:

D

Bohr's model correctly describes the hydrogen atom and other small atoms True or false????

False

Which of the following statements are false? I. It takes less energy to add an electron to nitrogen than to carbon because nitrogen will be closer to achieving a noble gas configuration II. It takes more energy to add an electron to fluorine than to oxygen because the radius of fluorine is smaller and more repulsion would occur in the p- orbitals III. It takes more energy to add an electron to nitrogen than to carbon because of the extra repulsions that would occur in the 2p orbitals IV. Less energy is released in adding an electron to iodine than chlorine because the radius of iodine is larger than the electron is added at a distance further from the nucleus

I, II

Which of the following represent a set of isotopes? Atomic nuclei containing: I. 20 protons and 20 neutrons II. 21 protons and 19 neutrons III. 22 neutrons and 18 protons IV. 20 protons and 22 neutrons V. 21 protons and 20 neutrons

I, IV, II, and V

Which of the following elements forms the most ionic bonds with chlorine?

K

Which of these is an isoelectronic series?

K+, Ca2+, Ar, S2-

The electron configuration of K is [Ar]4s^1 and that of Br is [Ar]4s^24p^5. What is the formula of the compound when these elements react?

KBr

What is the empirical formula for a compound that is 31.0% potassium, 28.9% chlorine, and 39.2% oxygen?

KClO3

An element has the electron configuration [Kr]5s^24d^105p^2. The element is a(n)

Metal

Which of the following has the smallest radius?

Mg2+

Without using any supplemental materials, predict which bond in each of the following groups will be the most polar. (use the expected trends found in the periodic table.)

O-H

A sample containing atoms of C and F was analyzed using x-ray photoelectron spectroscopy. The portion of the spectrum showing the 1s peaks for atoms of the two elements is shown below. Which of the following correctly identifies the 1s peak for the F atoms and provides an appropriate explanation? INSERT PICTURES

Peak X, because F has a greater nuclear charge than C has

Consider the ionization energy (IE) of the magnesium atom. Which of the following is not true?

The IE of Mg is lower than that of sodium

The elements C and Se have the same electronegativity value, 2.55. Which of the following claims about the compound that forms from C and Se is most likely to be true?

The carbon-to-selenium bond is nonpolar covalent

The photoelectron spectrum for the element nitrogen is represented above. Which of the following best explains how the spectrum is consistent with the electron shell model of the atom? *INSERT FREAKING PICTURE*

The electrons in the 2p sublevel have the smallest binding energy

Which is the best reason that the atomic radius generally increases with atomic number in each group of elements?

The number of energy levels increases

Lewis diagrams of molecules of three different hydrocarbons are shown below. Which of the following claims about the molecules is best supported by the diagrams? INSERT PICTURES

The strongest carbon-to-carbon bond occurs in molecules 3

1s^22s^22p^63s^23p^64s^23d^2 is the correct electron configuration for which of the following atoms?

Ti

The concept that electrostatic repulsion between electrons pairs surrounding an atom causes these pairs to be separated as far as possible is the foundation of

VSPER theory

Name the compound Zn3(PO4)2

Zinc Phosphate

The formula for carbon dioxide, CO2, can represent

all of the above - the combination of 1 atom of carbon and 2 atoms of oxygen - one molecule of carbon dioxide -1 mol of carbon dioxide molecules

As a general patter, electronegativity is inversely related to

atom size

One-half the distance between the nuclei of identical atoms that are bonded together is called the

atomic radius

The making of a bond is __________ and the breaking of a bond is __________

exothermic, endothermic

The first ionization energy of Mg is 73kJ/mol. The second ionization energy is

greater than 735 kJ/mol

In the alkaline-earth group, atoms with the smallest radii

have the highest ionization energy

Electron affinity tends to

increase across a period and decrease down a group

Within a group of elements, as the atomic number increases, the atomic radius

increases

Predict the type of bond one would expect to form between the following pair of elements: Mg and Br

ionic

The energy required to remove an electron from an atom is the atom's

ionization energy

The force between two bodies having identical electric charges......

is a force of repulsion

Select the correct molecular structure for the given species: CO2

linear

Bond energy is the energy

required to break a chemical bond

Bonding in molecules or ions that cannot be correctly represented by a single Lewis structure is

resonance

H-----X 𝛅+ 𝛅- What do the 𝛅+ and 𝛅- symbols indicate?

shared electrons will tend to be closer together

Because nuclear charge increases across a period, atoms become

smaller

H H \ . . | . . C == O + H---H --> H--- C --- O---H / . . | . . H H What is the hybridization of C before and after the reaction?

sp2 to sp3

A substance that contains a mixture of elements and possess metallic properties. Some host metal atoms are replaced by other metal atoms of similar size. These are called

substitutional alloy

An acid ending with the suffix -ic produces an anion with the

suffix -ate

All of the following are characteristics of metals except:

tend to gain electrons in chemical reactions

Select the correct molecular structure for the given species: H2O

tetrahedral