Questions | Answer | Explanations |
1 According to the wave-mechanical model of the atom, electrons in an atom
(1) travel in defined circles
(2) are most likely found in an excited state
(3) have a positive charge
(4) are located in orbitals outside the nucleus | 4 | wave-mechanical model probability of finding an electron |
2 What is the total charge of the nucleus of a carbon atom?
(1) –6 (3) +6
(2) 0 (4) +12 | 3 | carbon has 6 protons which is the charge of the nucleus |
3 A sample composed only of atoms having the same atomic number is classified as
(1) a compound (3) an element
(2) a solution (4) an isomer | 3 | definition of an element |
4 Which two particles each have a mass approximately equal to one atomic mass unit?
(1) electron and neutron
(2) electron and positron
(3) proton and electron
(4) proton and neutron | 4 | proton and neutrons ==> 1 amu electrons ==>1/1836 amu |
5 Which two characteristics are associated with metals?
(1) low first ionization energy and low electronegativity
(2) low first ionization energy and high electronegativity
(3) high first ionization energy and low electronegativity
(4) high first ionization energy and high electronegativity | 1 | use Table S |
6 Which element is most chemically similar to chlorine?
(1) Ar (3) Fr
(2) F (4) S | 2 | same group |
7 Which substance can be decomposed by chemical means?
(1) ammonia (3) phosphorus
(2) oxygen (4) silicon | 1 | definition of a compound |
8 When an atom loses one or more electrons, this atom becomes a
(1) positive ion with a radius smaller than the radius of this atom
(2) positive ion with a radius larger than the radius of this atom
(3) negative ion with a radius smaller than the radius of this atom
(4) negative ion with a radius larger than the radius of this atom | 1 | lose an electron the ion is smaller than the atom |
9 What is the name of the polyatomic ion in the compound Na2O2?
(1) hydroxide (3) oxide
(2) oxalate (4) peroxide | 4 | O22- perioxide see TABLE E |
10 Given the balanced equation:
I + I==> I2
Which statement describes the process represented by this equation?
(1) A bond is formed as energy is absorbed.
(2) A bond is formed and energy is released.
(3) A bond is broken as energy is absorbed.
(4) A bond is broken and energy is released. | 2 | see answer |