A naturally occurring sample of chlorine (Cl, atomic number = 17) has an atomic weight of 35.453 amu. Which of the following statements about chlorine is WRONG?
Select one:
A. All chlorine atoms have seventeen protons.
B. Chlorine atoms have three shells of electrons.
C. All chlorine atoms have a mass of 35.453 amu.
D. Chlorine atoms have seven valence electrons.
E. Chlorine atoms do not all have the same number of neutrons.
Which of the following statements about atoms are correct?
I. Almost all of the mass of the atom is due to the protons.
II. An atom is more than 10,000 times larger than its nucleus.
III. All atoms of the same element have the same number of protons.
IV. Protons and neutrons have the same charge.
V. Atoms in the same group of the Periodic Table have the same number of electron shells.
Select one:
A. I, III, and V.
B. All of these are correct.
C. II and III.
D. I, II, and V.
E. II, IV, and V.
Which of the statements about the effective nuclear charge, Zeff, is wrong?
Select one:
A. The value of Zeff is smaller than the value of Z because of repulsion between electrons.
B. The values of Zeff decrease on going across the periodic table from Na to Cl.
C. The value of Zeff is approximately the same for the atoms in the same column of the periodic table.
D. The value of Zeff for the calcium atom, Ca, Z = 20, is approximately 2+.
Which is the correct short-form electron configuration for the atoms in calcium nitride?
Select one:
a. Ca = [Ar], N = [Ne] 2s2 2p5.
b. Ca = [Ar] 4s2, N = [He] 2s2 2p3.
c. Ca = [Ar], N = [Ne]
d. Ca = [Ar], N = [He].
e. Ca = [Kr], N = [Ne].