Part A (45%) Answer all questions. For each statement or question, circle the le
ID: 547241 • Letter: P
Question
Part A (45%) Answer all questions. For each statement or question, circle the letter of the correct answer. 1. The number of electrons gained or lost when oxygen atom forms an ion is: a) one lost b) one gained c two gained d) two lost 2. The symbol for an ion with 13 protons and 10 electrons is a) Alb b) Na c)Ne d) Al 3. Which of the following elements has two valence electrons? a) magnesium b) bromine c) silicon d) none 4. Which element in each pair would be less electronegative? Circle the correct element a) beryllium; chlorine b) Fluorine; bromine c) phosphorus; calcium Which of the following pairs of elements would be expected to form a molecule with polar covalent bond? 5. a) hydrogen and hydrogen b) potassium and sulfur c) boron and nitrogen 6. Which of the following molecules would be expected to be polar? a) all b) H2 c) CHICI d) CH 91 92 93 94Explanation / Answer
1) d) O2- , 2 ELECTRONS ARE GAINED
2) d) Al3+
3) a) magnesium ( mg atomic no =12 , 2 e in valence shell)
4) d) phosphorus , calcium
5) c) boron and nitrogen
6) c) CH3Cl is polar compond