August 2015 Chemistry Regents #1-5
Highlight to reveal answers and explanations
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Questions | Answer | Links | Explanations |
| 1 Which subatomic particles are paired with their charges? (1) electron–positive, neutron–negative, proton–neutral (2) electron–negative, neutron–neutral, proton–positive (3) electron–negative, neutron–positive, proton–neutral (4) electron–neutral, neutron–positive, proton–negative | 2 | link | electron–negative, neutron–neutral, proton–positive just know it |
| 2 In the ground state, an atom of which element has two valence electrons? (1) Cr (3) Ni (2) Cu (4) Se | 3 | link | last number in an electron configuration |
| 3 The atoms in a sample of an element are in excited states. A bright-line spectrum is produced when these atoms (1) absorb energy (3) emit energy (2) absorb positrons (4) emit positrons | 3 | Link | electrons fall (higher to lower) releasing energy in the form of light |
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| 4 Which statement describes a concept included in the wave-mechanical model of the atom? (1) Positrons are located in shells outside the nucleus. (2) Neutrons are located in shells outside the nucleus. (3) Protons are located in orbitals outside the nucleus. (4) Electrons are located in orbitals outside the nucleus. | 4 | electrons travel in waves | |
| 5 All elements on the modern Periodic Table are arranged in order of increasing (1) atomic mass (2) molar mass (3) number of neutrons per atom (4) number of protons per atom | 4 | link | protons=atomic number |
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