All of the following are postulates of Dalton's atomic theory except

1.   ?    in a given compound, relative numbers of atoms of each kind are definite and constant.
2.   ?    elements are composed of atoms.
3.   ?    no atom is changed into another element in an ordinary chemical reaction.
4.   ?    compounds are formed when two or more atoms combine.
5.   ?    atoms are composed of electrons, protons, and neutrons.

J.J. Thomson determined that electrons are small, negatively charged particles by

1.   ?    bombarding gold foil with alpha particles.
2.   ?    exposing photographic plates to radioactive uranium.
3.   ?    deflecting cathode rays with electric and magnetic fields.
4.   ?    converting cathode rays to electron particles using a fluorescent screen.
5.   ?    decomposing neutrons into protons and electrons.

All of the following statements are true except

1.   ?    all atoms of a given element have the same mass number.
2.   ?    for any neutral element, the number of electrons is equal to the number of protons.
3.   ?    the mass number is the sum of the number of protons and neutrons.
4.   ?    isotopes of atoms contain the same number of protons but a different number of neutrons.
5.   ?    the atomic number equals the number of protons in an atom.

Which of the following two atoms have the same number of neutrons? ₈O-15, ₈O-16, ₉F-20, ₁₀Ne-20, ₁₁Na-22

1.   ?    ₈O-15 and ₈O-16
2.   ?    ₈O-16 and ₁₁Na-22
3.   ?    ₉F-20 and ₁₀Ne-20
4.   ?    ₉F-20 and ₁₁Na-22
5.   ?    ₁₀Ne-20 and ₁₁Na-22

How many electrons, protons and neutrons are found in a Cl^- ion formed from Cl-35?

1.   ?    17 electrons, 16 protons, 19 neutrons
2.   ?    17 electrons, 17 protons, 18 neutrons
3.   ?    18 electrons, 18 protons, 18 neutrons
4.   ?    18 electrons, 17 protons, 18 neutrons
5.   ?    18 electrons, 18 protons, 17 neutrons

Two isotopes of chlorine are found in nature, Cl-35 and Cl-37. The average mass of chlorine is 35.45u. The more abundant isotope of Cl has

1.   ?    17protons, 17 electrons and 18 neutrons
2.   ?    17protons, 17 electrons and 18.45 neutrons
3.   ?    17protons, 17 electrons and 20 neutrons
4.   ?    18 protons, 18 electrons and 17 neutrons
5.   ?    19protons, 19 electrons and 16 neutrons

What is the nuclear symbol for a species which contains 57 neutrons and has a mass number of 101?

1.   ?    Er
2.   ?    Ru
3.   ?    Md
4.   ?    La
5.   ?    Os

How many protons and electrons are in a sulfate ion, SO₄^2-?

1.   ?    46 protons and 48 electrons
2.   ?    48 protons and 48 electrons
3.   ?    48 protons and 50 electrons
4.   ?    50 protons and 48 electrons
5.   ?    None of the above

Identify the halogen from period 4.

1.   ?    Br
2.   ?    I
3.   ?    Kr
4.   ?    Ar
5.   ?    K

Which group of three elements contains a nonmetal, a metal and a metalloid?

1.   ?    Li, Al, Si
2.   ?    Na, Hg, I
3.   ?    I, Hg, Si
4.   ?    K, O, Br
5.   ?    H, Al, N

Which group of three elements contains an alkaline earth metal, a halogen, and a post-transition element?

1.   ?    Be, S, U
2.   ?    Ba, As, Ce
3.   ?    U, Cl, Rb
4.   ?    Mg, Br, Pb
5.   ?    K, Ga, Se

What is the correct name for K₃PO₄?

1.   ?    tripotassium phosphate
2.   ?    potassium(I)monophosphorus tetraoxide
3.   ?    potassium(I) phosphate
4.   ?    potassium phosphate
5.   ?    potassium phosphide

What is the correct name for aluminum selenide?

1.   ?    AlSe
2.   ?    AlSe₂
3.   ?    Al₂Se
4.   ?    Al₂Se₃
5.   ?    Al₃Se₂

What is the formula for chlorous acid?

1.   ?    HCl
2.   ?    HClO
3.   ?    HClO₂
4.   ?    HClO₃
5.   ?    HClO₄

What is the correct name for PF₅?

1.   ?    phosphorus pentafluoride
2.   ?    phosphorus(V) fluoride
3.   ?    phosphorofluoride
4.   ?    pentafluorophosphorus
5.   ?    pentafluorophosphate