Nature
Which statement describes the earliest model of the atom?
(1) An atom is an indivisible hard sphere.
(2) An atom has a small, dense nucleus.
(3) Electrons are negative particles in an atom.
(4) Electrons in an atom have wave-like properties.
(1) An atom is an indivisible hard sphere.
Strontium and barium have similar chemical properties because atoms of these elements have the same number of
(1) protons
(2) neutrons
(3) electron shells
(4) valence electrons
(4) valence electrons
The only two elements in alkenes and alkynes are
(1) carbon and nitrogen
(2) carbon and hydrogen
(3) oxygen and nitrogen
(4) oxygen and hydrogen
(2) carbon and hydrogen
In which reaction is an atom of one element converted into an atom of another element?
(1) combustion
(2) fermentation
(3) oxidation-reduction
(4) transmutation
(4) transmutation
Which equation represents a conservation of atoms?
(1) 2Fe + 2O₂ → Fe₂O₃
(2) 2Fe + 3O₂ → Fe₂O₃
(3) 4Fe + 2O₂ → 2Fe₂O₃
(4) 4Fe + 3O₂ → 2Fe₂O₃
(4) 4Fe + 3O₂ → 2Fe₂O₃
In all atoms of bismuth, the number of electrons must equal the
(1) number of protons
(2) number of neutrons
(3) sum of the number of neutrons and protons
(4) difference between the number of neutrons and protons
(1) number of protons
Which term represents the fixed proportion of elements in a compound?
(1) atomic mass
(2) molar mass
(3) chemical formula
(4) density formula
(3) chemical formula
Which functional group contains a nitrogen atom and an oxygen atom?
(1) ester
(2) ether
(3) amide
(4) amine
(3) amide
Which electron shell in an atom of calcium in the ground state has an electron with the greatest amount of energy?
(1) 1
(2) 2
(3) 3
(4) 4
(4) 4
In terms of disorder and energy, systems in nature have a tendency to undergo changes toward
(1) less disorder and lower energy
(2) less disorder and higher energy
(3) greater disorder and lower energy
(4) greater disorder and higher energy
(3) greater disorder and lower energy
Which symbol represents a particle that has a mass approximately equal to the mass of a neutron?
(1) α
(2) β-
(3) β+
(4) p
(4) p
Given the equation representing a reaction:
H + H → H₂
What occurs during this reaction?
(1) A bond is broken and energy is absorbed.
(2) A bond is broken and energy is released.
(3) A bond is formed and energy is absorbed.
(4) A bond is formed and energy is released.
(4) A bond is formed and energy is released.
Which radioisotope requires long-term storage as the method of disposal, to protect living things from radiation exposure over time?
(1) Pu-239
(2) Fr-220
(3) Fe-53
(4) P-32
(1) Pu-239
Based on Table I, which equation represents a reaction with the greatest difference between the potential energy of the products and the potential energy of the reactants?
(1) 4Al(s) + 3O₂(g) → 2Al₂O₃(s)
(2) 2H₂(g) + O₂(g) → 2H₂O(l)
(3) C₃H₈(g) + 5O₂(g) → 3CO₂(g) + 4H₂O(l)
(4) C₆H₁₂O₆(s) + 6O₂(g) → 6CO₂(g) + 6H₂O(l)
(1) 4Al(s) + 3O₂(g) → 2Al₂O₃(s)
Given the equation representing a system at equilibrium in a sealed, rigid container:
2HI(g) <--> H₂(g) + I₂(g) + energy
Increasing the temperature of the system causes the concentration of
(1) HI to increase
(2) H₂ to increase
(3) HI to remain constant
(4) H₂ to remain constant
(1) HI to increase
An orbital is a region in an atom where there is a high probability of finding
(1) an alpha particle
(2) an electron
(3) a neutron
(4) a positron
(2) an electron
Distillation is a process used to separate a mixture of liquids based on different
(1) boiling points
(2) densities
(3) freezing points
(4) solubility
(1) boiling points
Which statement describes the reactions in an electrochemical cell?
(1) Oxidation occurs at the anode, and reduction occurs at the cathode.
(2) Oxidation occurs at the cathode, and reduction occurs at the anode.
(3) Oxidation and reduction both occur at the cathode.
(4) Oxidation and reduction both occur at the anode.
(1) Oxidation occurs at the anode, and reduction occurs at the cathode.
What is the molarity of 2.0 liters of an aqueous solution that contains 0.50 mole of potassium iodide, KI?
0.25 M
At which temperature and pressure will a sample of neon gas behave most like an ideal gas?
(1) 300. K and 2.0 atm
(2) 300. K and 4.0 atm
(3) 500. K and 2.0 atm
(4) 500. K and 4.0 atm
(3) 500. K and 2.0 atm
What is the color of bromcresol green indicator in a solution with a pH value of 2.0?
yellow
Which equation represents a spontaneous reaction?
(1) Ca + Ba²⁺ → Ca²⁺ + Ba
(2) Co + Zn²⁺→ Co²⁺ + Zn
(3) Fe + Mg²⁺ → Fe²⁺ + Mg
(4) Mn + Ni²⁺ → Mn²⁺ + Ni
(4) Mn + Ni²⁺ → Mn²⁺ + Ni
When a sample of Mg(s) reacts completely with O2(g), the Mg(s) loses 5.0 moles of electrons. How many moles of electrons are gained by the O2(g)?
5.0 mol
In which type of nuclear reaction do nuclei combine to form a nucleus with a greater mass?
fusion
What is the chemical name of the compound NH₄SCN?
ammonium thiocyanate