January 2010 Chemistry Regents #1-10
Highlight to reveal answers and explanations
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Questions |
Answer | Explanations |
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1 Which two particles have opposite charges? (1) an electron and a neutron (2) an electron and a proton (3) a proton and a neutron (4) a proton and a positron |
2 | protons + electrons - |
| 2 Which statement describes how an atom in the ground
state becomes excited? (1) The atom absorbs energy, and one or more electrons move to a higher electron shell. (2) The atom absorbs energy, and one or more electrons move to a lower electron shell. (3) The atom releases energy, and one or more electrons move to a higher electron shell. (4) The atom releases energy, and one or more electrons move to a lower electron shell. |
1 | see answer |
| 3 An element that has a low first ionization energy and
good conductivity of heat and electricity is classified as a (1) metal (3) nonmetal (2) metalloid (4) noble gas |
1 | see table S then use the PT to see location |
| 4 The chemical properties of calcium are most similar to
the chemical properties of (1) Ar (3) Mg (2) K (4) Sc |
3 | same group |
| 5 Which element is a liquid at STP? (1) argon (3) chlorine (2) bromine (4) sulfur |
2 | bromine and mercury are the only liquids |
| 6 Which statement describes a chemical property of
aluminum? (1) Aluminum is malleable. (2) Aluminum reacts with sulfuric acid. (3) Aluminum conducts an electric current. (4) Aluminum has a density of 2.698 g/cm3 at STP. |
2 | chemical properties look for the reaction |
| 7 Which element has an atom in the ground state with a
total of three valence electrons? (1) aluminum (3) phosphorus (2) lithium (4) scandium |
1 | group 13, use PT, last number of electrons |
| 8 Which substance can be broken down by chemical means? (1) magnesium (3) mercury (2) manganese (4) methanol |
4 | definition of a compound 3 wrong answers are elements |
| 9 The gram-formula mass of NO2 is defined as
the mass of (1) one mole of NO2 (2) one molecule of NO2 (3) two moles of NO (4) two molecules of NO |
1 | see answer |
| 10 In which type of reaction do two or more substances
combine to produce a single substance? (1) synthesis (2) decomposition (3) single replacement (4) double replacement |
1 | A + B ==> AB synthesis |