January 2017 Chemistry Regents #31-35
Highlight to reveal answers and explanations
| |||
Questions | Answer | Links | Explanations |
31 Which electron configuration represents the distribution of electrons in a potassium atom in the ground state? (1) 2-8-8-1 (3) 2-8-5 (2) 2-8-7-2 (4) 2-7-6 | 1 | 2-8-8-1
see PT cell for element K...not P | |
32 At STP, which element is malleable and a good conductor of electricity? (1) xenon (3) platinum (2) silicon (4) hydrogen | 3 | which is a metal? left side of PT | |
33 Which general trends in atomic radius and electronegativity are observed as the elements in Period 3 are considered in order of increasing atomic number? (1) Atomic radius decreases and electronegativity increases. (2) Atomic radius increases and electronegativity decreases. (3) Both atomic radius and electronegativity increase. (4) Both atomic radius and electronegativity decrease. | 1 | left to right I.E. increases and so does EN | |
| |||
34 What is the chemical name for Na2SO3? (1) sodium sulfite (3) sodium sulfide (2) sodium sulfate (4) sodium thiosulfate | 1 | sodium sulfate | |
35 Which molecular formula is also an empirical formula? (1) C6H6 (3) N2H4 (2) H2O2 (4) N2O5 | 4 | lowest whole number ratio...which can not be reduced any lower? | |
|