BJU Chemistry midterm
0 K° = ?
-273°C
How many significant figures are in 100000000?
1
How many significant figures? 1000 mL
1
What is the correct coefficient to balance this equation? NH₄NO₂->N₂+H₂O
1,1,2
What is the measure of a tetrahedral bond angle?
109.5 degrees
How old do scientists think the universe is?
13.8 billion years old
Which electron configuration matches the oxygen atom?
1s²2s²2p⁴
Which is the electron configuration for an oxygen atom?
1s²2s²2p⁴
What is the electron configuration of iron?
1s²2s²2p⁶3s²3p⁶4s²3d⁶
Which electron configuration belongs to copper?
1s²2s²2p⁶3s²3p⁶4s²3d⁹
How many atoms of nitrogen are present in this molecule? Pb(NO₃)₂
2
How many electrons can occupy any single subshell orbital?
2
How many significant figures: 0.012 km?
2
Which of the elements in the picture has correct electron dot notation?
2
What elements generally make a covalent bond?
2 or more nonmetals
Balance the following equation: Cr(s) + Fe(NO₃)₂(ag)->Fe(s)+Cr(NO₃)₃(ag)
2,3,3,2
Convert 72°F to Celsius (5/9 x (°F-32))?
22.2°C
Identify the reactants in this equation? 2H₂+O₂->2H₂O
2H₂+O₂ (A)
How many significant figures: 216 m?
3
How many significant figures: 6.50 x 10⁴?
3
How many significant figures: 153.0 mL?
4
How many 4d orbitals are there in an atom?
5
How many sigma and pi bonds does this have?
5 sigma and 0 pi
A metal has a density of 10.8 g/cm³. What is the volume if the mass is 560 g?
51.9 cm³
Convert 253°C to K?
526°K
How many electrons can be found in a P orbital?
6
How many significant figures: 100.000 cL?
6
How many valence electrons does chlorine have?
7
The International System of Units only includes how many base units?
7
How many valence electrons does argon have?
8
What is the correct structure for BF₃?
A
All of the following are Dalton's postulates EXCEPT what?
A given chemical compound always contains the same element in the exact same proportions by mass
All of the following are one of Dalton's Postulates EXCEPT for what?
A given chemical compound always contains the same elements in the exact same proportions by mass
What is a homogeneous mixture?
A mixture that is the same throughout
For an electron to change from ground state to an excited state it must what?
Absorb energy
Who developed lab procedures but did not perform controlled experiments like true scientist?
Alchemist
Which statement BEST summarizes the particulate theory of matter? (multi)
All matter are made of tiny particles that are in constant motion, have force of attraction between them, and occupies space; All matter has particles, motion, force, and space
What is the correct name for Al₂O₃?
Aluminum oxide
Name the compound NH₄F?
Ammonium flouride
The base for the current SI system is what?
Ampere
When a nonmetal gains electrons, it becomes what type of ion?
Anion
Which of the following is a P block element?
Argon (Ar)
In a polar covalent bond, which atom will have a partial positive charge? (choose 2 correct answers)
Atom that attracts fewer electrons; The atom with the lower electronegativity
Electrons occupy orbitals of lowest energy first is part of what electron configuration rule?
Aufbau Principle
Who discovered spontaneous emission of radiation from the nucleus?
Becquerel
Who discovered spontaneous emission of radiation in the nucleus?
Becquerel
What is the correct shape for this molecule?
Bent
Who developed the planetary model that electrons move in circular orbits within specific energy levels?
Bohr
Who developed the planetary model, that electrons move in circular orbits within specific energy levels?
Bohr
Which element has the smaller atomic radius: potassium (K) or bromine (Br)?
Bromine
The above image of KMnO₄ (Potassium Permanganate) dissolving in water is an example of which evidence(s) of the particulate theory of matter?
Brownian's motion; diffusion
Name this compound? Ca(CO₃)
Calcium carbonate
An electron cloud can what?
Can be called an orbital
The base for the luminous intensity in the SI system is what?
Candela
When a metal loses electrons, it becomes what type of ion?
Cation
Who discovered neutrons, a neutral particles in the nucleus of an atom?
Chadwick
Who discovered neutrons, the neutral particles in the nucleus of an atom?
Chadwick
Elements in an elemental family have similar what?
Chemical properties
What is a halogen?
Chlorine
Which element has the greatest ionization energy: Aluminum (Al) or Chlorine (Cl)?
Chlorine (Cl)
Name the following ionic compound: Cr(NO₂)₃?
Chromium (III) Nitrite
What is the name for CrN?
Chromium (III) nitride
What is the number in blue (brackets)? [2]Mg(NO₃)₂(aq)
Coefficient
Substance made from two or more combined atoms?
Compound
What are made from a combination of 2 or more elements in a constant ratio?
Compounds
How do the following two elements bond together?
Cr₂O₃
What is the formula for copper(I) sulfate?
Cu₂SO₄
If waves can behave like particles, then particles can behave like a wave. This is the idea behind what?
DeBroglie waves
Atomic radius _________ going across a row, and _________ going down a group?
Decreases, increases
Who was the first to propose that matter was composed of tiny indivisible particles? (His work was NOT based on experimental data)
Democritus
Who was the first to propose that matter was composed of tiny indivisible particles? His work was NOT based on experimental data.
Democritus
When a gas changes directly to a solid, the process is known as what?
Deposition
What are the shapes of P orbitals?
Dumbbells
When electrons reach an "excited" state, what lines are produced?
Emission (bright)
Sigma bonds are formed by what?
End to end overlap of S orbitals
Ionization energy is what?
Energy needed to remove the outermost electron
The electrons in a nonpolar covalent molecule are shared how?
Evenly
A gas has what?
Fast moving particles
What does this picture represent? (10 particles are seen spaced out from each other)
Gas
What is the formula for hydrochloric acid?
HCl
What is the formula for perchloric acid?
HClO₄
Which of the following molecules, based on the elements present, would be most polar?
HF
What does this symbol Δ above the arrow mean?
Heat is supplied
A mixture that is NOT evenly distributed?
Heterogeneous
Periods on the periodic table are what?
Horizontal rows
Which elements are the most abundant in the visible universe?
Hydrogen and helium
Which of the following is a polar molecule?
H₂O
What is the formula for Hydrosulfuric Acid?
H₂S
Predict the bond that will form between Sr and S?
Ionic
What is the name of FeCl₃? (Hint: think about what type of metal Fe is)
Iron (III) Chloride
What is the one thing responsible for a metal being malleable, ductile, and conductive?
Its sea of free-floating electrons
What is this element? 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶
Krypton
Which of the following are base units?
L; s; g
What is the name of the top row of the two lines of elements found at the bottom of the periodic table?
Lanthanides
PbS₂?
Lead (IV) sulfide
When forming an ionic bond, a metal atom will?
Looses electrons to form a cation
What is the formula to solve for the neutron?
Mass + atomic number = neutrons
The basic unit length of the SI system is what?
Meter
The proper formula for magnesium hydroxide is what?
Mg(OH)₂
A combination that can be separated by physical processes is a what?
Mixture
What is the VSEPR theory used to predict?
Molecular shape
The modern periodic table arrangement used today was devised by who?
Mosley
What is TRUE for metalloids?
Must touch the stair-step line
What is the formula for sodium nitrate?
Na(NO₃)
Which element is pictured? (2p^v^v^v 2s^v 1s^v)
Neon
Which element has the greatest electronegativity: Nitrogen (N) or Arsenic (As)?
Nitrogen
What elements generally make an ionic bond?
Nonmetal and metal
Anions are _________ that form ________ ions and ____ electrons
Nonmetals, negative, gain
What is the formula for TETRAnitrogen NONoxide? (Hint: this is the only bond WITH prefixes)
N₄O₉
Which Lewis dot model correctly shows an O₂ molecule?
O=O
The diagram above represents two elements with what? (^v)
Opposite spins
Phosphorous trichloride?
PCl₃
In chemical compounds, covalent bonds form when?
Pairs of electrons are shared between two nonmetal atoms
Which compound is formed as a precipitate in this reaction? Pb(NO₃)₂(aq)+2KI(aq)->PbI₂+2KNO₃(aq)
PbL2
Which element would have the largest atomic radius?
Phosphorus
Name the acid: H₃PO₃?
Phosphorus acid
A student poured three samples of solution. In their beaker, they had 22.5 ml, 22.4 ml and 22.8 ml. They needed 26 ml per sample. Were they accurate or precise in their measurements?
Precise
Is the following a pure substance or a mixture? (NaHCO₃)
Pure substance
Particles whose motions are better described by quantum mechanics can only gain or lose energy in discrete units called what?
Quanta
DeBroglie's equation?
Related to the movement of mass to its wavelength
Who discovered the nucleus and nuclear atom with the Gold Foil experiment?
Rutherford
Who said that in the quantum mechanical or electron cloud model, electron orbitals are regions around the nucleus where electrons are likely to be found?
Schrödinger
Who determined that electron paths cannot be predicted and exist inside the electron cloud?
Schrödinger and Heisenberg
What is the correct Lewis dot structure for ammonia NH3?
See pic
Balance the equation Si(OH)₄+NaBr->SiBr₄+NaOH
Si(OH)₄+4NaBr->SiBr₄+4NaOH
What is the correct formula for this molecule?
SiF₄
A π (pi) bond is the result of what?
Sideways overlap of two horizontal P orbitals
Which is the stronger bond?
Sigma bond (undefined)
What is the name for SiCl₄?
Silicon tetrachloride
What state of matter is this substance? NaOH(s)
Solid
Which state of matter has particles arranged like this? (A cube made out of particles packed closely together into a cube shape)
Solid
Light emitted from a star or galaxy can be separated into a band of colors, called what?
Spectrum
What does Hund's rule state?
States that single electrons with the same spin must occupy each energy orbital before additional electrons with opposite spins can occupy the same orbitals
What term describes a solid changing to a gas?
Sublimation
What are the blue numbers called? (brackets) Pb(NO[₃])[₂]
Subscripts
The correct shape for this molecule?
Tetrahedral
In a polar covalent bond, the electrons gather around what?
The atom with the greatest electronegativity
At the end of chemical reactions, what is the total mass of the reactants compared to the total mass of the products?
The mass is the same
Brownian's motion BEST serves as evidence for which of the following?
The particles are in constant motion
Jimmy wants to use the water displacement method to find the volume of a small rock. He pours 10 mL of water into a graduated cylinder, then drops in the rock. How will Jimmy be able to determine the rock's volume?
The volume of the rock will equal the difference between the initial and final volumes of the water in the graduated cylinder
What do electrons do in a metallic bond?
They float around freely
He discovered electrons and proposed the "plum-pudding model"?
Thomson
Who discovered electrons and proposed the "plum-pudding" model of the atom?
Thomson
What is the name of the compound SnO₂?
Tin (IV) Oxide
Which area on the periodic table represents the electrons in the D sublevel?
Transition elements
What is the correct shape for the molecule?
Trigonal planar
There are four different types of subshells S,P,D,F?
True
Identify the element for [Xe]6s²4f¹⁴5d⁴
Tungsten
The electrons in a polar covalent molecule are shared how?
Unevenly
Each element on the periodic table can be identified by its what?
Unique spectral fingerprint
Lewis dot structure shows us the what?
Valence electrons
An ionic bond forms when?
Valence electrons are transferred between atoms
Which color on the image of the periodic table corresponds with the actinides?
Yellow on the bottom
What is the noble gas configuration for beryllium?
[He]2s²
What is the noble gas configuration for neon?
[Ne]
What is the noble gas configuration for phosphorus?
[Ne] 3s² 3p³
What does the Pauli Exclusion Principle state?
a maximum of two electrons can occupy a single atomic orbital, but only if the electrons have opposite spins
