August 2006 Chemistry Regents #1-10
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Questions 1-10 Questions 11-20 Questions 21-30 Questions 31-40 Questions 41-50 |
Questions | Answer | Explanations |
| 1 Which statement correctly describes the charge of the nucleus and the charge of the electron cloud of an atom? (1) The nucleus is positive and the electron cloud is positive. (2) The nucleus is positive and the electron cloud is negative. (3) The nucleus is negative and the electron cloud is positive. (4) The nucleus is negative and the electron cloud is negative. | 2 | structure of the atom + nucleus, cloud of electrons is negative |
| 2 Which Period 4 element has the most metallic properties? (1) As (3) Ge (2) Br (4) Sc | 4 | one on the left side |
| 3 Which property makes it possible to separate the oxygen and the nitrogen from a sample of iquefied air? (1) boiling point (3) hardness (2) conductivity (4) electronegativity | 1 | boiling points are different |
| 4 Which statement explains why ozone gas, O3, and oxygen gas, O2, have different properties? (1) They are formed from different elements. (2) They have different molecular structures. (3) They have different oxidation numbers. (4) They have different electronegativities. | 2 | their molecules are different |
| 5 Which statement is true about oxidation and reduction in an electrochemical cell? (1) Both occur at the anode. (2) Both occur at the cathode. (3) Oxidation occurs at the anode and reduction occurs at the cathode. (4) Oxidation occurs at the cathode and reduction occurs at the anode. | 3 | An OX Red CAT |
| 6 A compound is made up of iron and oxygen, only. The ratio of iron ions to oxide ions is 2:3 in this compound. The IUPAC name for this compound is (1) triiron dioxide (3) iron(III) oxide (2) iron(II) oxide (4) iron trioxide | 3 | Fe2O3 now name it |
| 7 Which process is a chemical change? (1) melting of ice (2) boiling of water (3) subliming of ice (4) decomposing of water | 4 | look for a reaction |
| 8 Which substance contains bonds that involved the transfer of electrons from one atom to another? (1) CO2 (3) KBr (2) NH3 (4) Cl2 | 3 | transfer=IONIC=metal and nonmetal |
| 9 What is the total number of pairs of electrons shared in a molecule of N2? (1) one pair (3) three pairs (2) two pairs (4) four pairs | 3 | N2= has a triple bond (3 pairs or 6 electrons) |
| 10 Which formula represents a nonpolar molecule containing polar covalent bonds? (1) H2O (3) NH3 (2) CCl4 (4) H2 | 2 | H2 non polar bonds (OUT) NH3, H2O are polar CCl4 symmetrical and the bonds are between 2 different atoms |