What is the nuclear charge for the following atoms: Na, F, Sn? a. 10, 9, 50 b. 11, 9, 50 c. 10, 10, 51 d. 11, 9, 51
Calculate the number of neutrons, electrons, and protons that are present in 52Cr3+? a. 26p+, 26n, 26e- b. 24p+, 28n, 21e- c. 26p+, 27n, 26e- d. 52p+, 52n, 52e-
Which of the following is the correct electron configuration for Zn2+ (note: atomic number of Zn is 30) a. 1s22s22p63s23p64s03d10 b. 1s22s22p63s23p64s23d7 c. 1s22s22p63s23p64s23d10 d. 1s22s22p63s23p64s23d8 What does atom contain?
A. proton(s), neutron(s), electron(s)
b. proton(s), electron(s), quark(s)
c. proton(s), nucleus, neutron(s)
d. proton(s), neutron(s), electron(s) (and proton and electron only for 1H)
e. proton(s), electron(s), nucleus
The charge of cations and anions are , respectively? __ A. negative and positive b. neutral and positive c. positive and negative d. positive and neutral
What is the maximum number of electrons allowed in a single atomic energy level in
terms of the principal quantum number n? A. 2n2 + 24 b. 2n + 2 c. 2n d. 2n2
How to name ionic compound correctly?
A. the positive ion first and the negative ion second
b. the cation first and the anion second
c. the anion first and the cation second
d. A & B (the positive ion first and the negative ion second OR the cation first and the anion second)
How many atoms are present in 123 g of magnesium cyanide? A. 4.85 x 1024 b. 2.81 x 1028 c. 2.91 x 1024 d. 9.7 x 1023
Which of the following compounds is not a possible isotope of carbon? A. 13C b. 6C c. 14C d. 12C
Which statement is FALSE about valence electrons?
a.The number of valence electron is always larger than 8
b.Oxygen atom has 6 valence electrons
c.Atoms are reactive unless they have a full valence shell of electrons.
d.Valence electrons are in the outermost electron shell
Which is a list of elements listed in order of increasing ionization energy? A. Br, Cl, F b. Al, Mg, Na c. Na, K, Rb d. Ne, Ar, Kr
Distinguish between monoatomic and polyatomic ions
a. a monoatomic ion contains only one kind of atom while polyatomic ion contains more than one atom.
B. a monoatomic ion contains only one kind of atom while polyatomic ion contains less than one atom.
C. a monoatomic ion contains more than one kind of atom while polyatomic ion contains only one atom.
D. a monoatomic ion contains only two kind of atom while polyatomic ion contains more than two atom.
What type of bonds are found in molecular compounds? A. Covalent bonding b. Hydrogen bonding c. Ionic bonding d. None of them
Organic chemistry studies molecules [1], Organic molecules [2]. On the other hand,
inorganic chemistry learns about the compounds [3]. Inorganic compounds can be classified as [4].
A. acid, base, salt, and oxides
B. make up building blocks for living things
C. containing carbon-hydrogen bond
D. which do not involve in carbon-hydrogen bond
P/s: Please input the definite character only. For example: If the answer is 1C, input C only. (NOT c) 1.C 2.B 3.D 4.A
The atomic number (Z) is the number of __ in the atom's nucleus a. proton(s) and electron(s) b. proton(s) and neutron(s) c. proton(s) d. neutron(s)
Which is the net charge of these following ions: 130I- , 107Ag+ , 119Sn2+ a. 2+; 1-; 1+ b. 1+; 2+; 1- c. 1+; 1-; 2+ d. 1-; 1+; 2+
If an atom has the electron configuration 1s22s22p5 , how many electrons must it gain to achieve an octet? A. 1 b. 2 c. 4 D.3
Chlorine forms 4 oxoanions, namely ClO4-, ClO3-, ClO2- and ClO-, which one is hypochlorite? A. ClO- b. ClO2- c. ClO4- d. ClO3-
What is the ground state electron configuration of Si (given Si has 14 protons)? A. 1s22s22p53s33p2 b. 1s22s22p63s13p3 c. 1s22s22p63s23p2 d. 1s22s22p43s13p3
Calcium reacts with element X to form an ionic compound. If the ground-state electron
configuration of X is 1s22s22p4 , what is the simplest formula for this compound? A. CaX b. Ca4X2 c. Ca2X2 d. CaX2 An atom consists of _ a. Nucleus and Electrons b. Protons
c. Protons, Neutrons and Electrons d. Electrons e. Neutrons
The atomic mass of hydrogen is 1.008 amu. What is the percent composition of
hydrogen by isotope, assuming that hydrogen’s only isotopes are 1H and 2D? A. 92% H, 8% D b. 99.92% H, 0.08% D c. 99.2% H, 0.8% D d. 99.992% H, 0.008% D
What is the total concentration of ions in a 0.40 M solution of K2CO3? a. 1.262 b. 1.20 c. 1.26 d. 1.202
What is the molecular formula for aluminium sulfate? a. Al3(SO4)2 b. Al2(SO4)3 c. Al2SO3 d. Al2(SO3)3
Matching the right name for each chemical formula. Na2O - sodium oxide CO2 – carbon dioxide CuO - cupric oxide NH4OH - amonium hydroxide
P2O5 - disphosphorus pentaoxide Cu2O - cuprous oxide
Example of Law of Definite Composition
a. In 42g sodium fluoride, there are 23g sodium and 19g fluoride, while in 8.4g sodium
flouride, there are 4.6g sodium and 3.8g fluoride
b. No matter how much CO2 weigh, the ratio between mass of C and O is always 0.375 (giving AC = 12, AO = 16) c. A and B are correct d. A and B are not correct
In a neutral atom, the number of electrons is equal to the number of __ a. proton(s) and neutron(s) b. neutron(s) c. proton(s) d. proton(s) and electron(s)
An ordinary hydrogen atom consists of _ (normally called) a. None of the above b. 1 proton with 1 electron
c. 1 proton, 2 neutrons with 1 electron
d. 1 proton, 1 neutron with 1 electron
Which atom will have the largest radius in each pair: (a) K, Na (b) K, Br (c) Br, Br- a. Na, Br, Br b. Na, K, Br c. Na, K, Br- d. K, K, Br-
Gallium has two naturally occurring isotopes, 69Ga (isotopic mass 68.9256 amu,
abundance 60.11%) and 71Ga (isotopic mass 70.9247 amu, abundance 39.89%).
Calculate the atomic mass of gallium. A. 71.25 amu b. 69.72 amu c. 65.48 amu d. 70.12 amu
Which statement is TRUE about isotope?
A. Isotopes of an element have different masses
b. All isotopes of an element are chemically identical
c. Isotopes are identified by their mass numbers d. All of the above
For a hydrogen atom, how many electrons are needed in the valence electron shell to be stable? A. 1 b. None of them c. 8 d. 2 e. 3
Silicon (Si) is essential to the computer industry as a major component of
semiconductor chips. It has three naturally occurring isotopes: 28Si, 29Si, and 30Si.
Determine the numbers of neutrons in each silicon isotope respectively. Given atomic number of silicon is 14. A. Not listed here b. 14, 15 and 16 c. 16, 15 and 14 d. 14, 14, and 14
Which is the electron configuration for each of the Br-? A. [Ar]3d4 b. [Ar]3d8 c. [Kr] d. [Ar]4s23d104p6
Which pair of elements has the most similar properties? A. Cl, O b. P, N c. S, P d. N, Cl
The strength of the ionic bonding depends on a. the distance b. charge c. size d. both distance and charge
Which of the following equations describes the maximum number of electrons that can fill a sub-shell (s, p, d, f)? a. 2l + 2 b. 4l + 2 c. 2l2 d. 2l2 + 2