January 2014 Chemistry Regents #1-10
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Questions | Answer | Links | Explanations |
1 What is the approximate mass of a proton? (1)1 u (3) l g (2) 0.0005 u (4) 0.0005 g | 1 | link | protons mass= 1 atomic mass unit = 1 u |
2 An electron in a sodium atom gains enough energy, to move from the second shell to the third shell. The sodium atom becomes (1) a positive ion (2) a negative ion (3) an atom in an excited stale (4) an atom in the ground state | 3 | link | electrons occupying higher energy levels when there are lower levels available are considered to be excited. Since the electron is still part of the atom and has not been removed it is still an atom and not an ion. |
3 Which particle has no charge? (1) electron (3) positron (2) neutron (4) proton | 2 | link | neutrons are neutral |
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4 Which quantity represents the number of protons in an atom? (1) atomic number (2) oxidization number (3) number of neutrons (4) number of valence electrons | 1 | link | atomic number of an atom is the number of protons. * It is also the electrons, since "atoms" are neutral. |
5 The element sulfur is classified as a (1) metal (3) nonmetal (2) metalloid (4) noble gas | 3 | link | nonmetals are on the left of the staircase on the periodic table |
6 The elements in Group 2 have similar chemical properties because each atom or these elements has the same (1) atomic number (2) mass number (3) number of electron shells (4) number of valence electrons | 4 | link | Same group, same number of valence electrons. |
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7 What is formed when two atoms of bromine bond together? (I) a monatomic molecule (2) a diatomic molecule (3) a heterogeneous mixture (4) a homogeneous mixture | 2 | link | diatomic=2 atoms molecule= covalent structure |
8 Gold can be flattened into an extremely thin sheet. The malleability of gold is due to the (I) radioactive decay, mode of the isotope An-19S (2) proton-to-neutron ratio in an atom of gold (3) nature of the bonds between gold atoms (4) reactively of gold atoms | 3 | link | malleability is due to metal atom being able to shift position and still be bonded |
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9 Which term represents the attraction one atom has for the electrons in a bond from another atom? (1) electronegativity (2) electrical cond1lctivity (3) first ionization energy (4) mechanical energy | 1 | link | definition of electronegativity |
10 Salt water is classified as a (1) compound because the proportion or its atoms is fixed (2) compound because the proportion of its atoms can vary (3) mixture because the proportion of its components is fixed (4) mixture because the proportion of its components can vary | 4 | link | salt water is a mixture and you can adjust the amount dissolved by adding more |